pytest: try to fix reckless flake.

Seems like it's using an old version of pyln-client, which had the bug
of referring to long_desc:

```
def test_local_dir_install(node_factory):
        """Test search and install from local directory source."""
        n = get_reckless_node(node_factory)
        n.start()
        r = reckless([f"--network={NETWORK}", "-v", "source", "add",
                      "tests/data/recklessrepo/lightningd/testplugpass"],
                     dir=n.lightning_dir)
        assert r.returncode == 0
        r = reckless([f"--network={NETWORK}", "-v", "install", "testplugpass"], dir=n.lightning_dir)
        assert r.returncode == 0
>       assert 'testplugpass enabled' in r.stdout
E       assert 'testplugpass enabled' in '[2024-11-14 06:47:12,999] DEBUG: Searching for testplugpass\nfound testplugpass in source: tests/data/recklessrepo/lightningd/testplugpass\n[2024-11-14 06:47:13,031] DEBUG: entry: testplugpass.py\n[2024-11-14 06:47:13,031] DEBUG: Retrieving testplugpass from tests/data/recklessrepo/lightningd/testplugpass\n[2024-11-14 06:47:13,032] DEBUG: Install requested from InstInfo(testplugpass, tests/data/recklessrepo/lightningd/testplugpass, None, testplugpass.py, requirements.txt, None).\n[2024-11-14 06:47:13,032] DEBUG: copying local directory contents from tests/data/recklessrepo/lightningd/testplugpass\n[2024-11-14 06:47:13,038] DEBUG: cloned_src: InstInfo(testplugpass, /tmp/reckless-0721411112afw6ng7/clone, None, testplugpass.py, requirements.txt, testplugpass)\n[2024-11-14 06:47:13,038] DEBUG: using installer python3venv\n[2024-11-14 06:47:13,038] DEBUG: creating /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass\n[2024-11-14 06:47:13,038] DEBUG: creating /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/source\n[2024-11-14 06:47:13,038] DEBUG: copying /tmp/reckless-0721411112afw6ng7/clone/testplugpass tree to /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/source/testplugpass\n[2024-11-14 06:47:13,039] DEBUG: linking source /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/source/testplugpass/testplugpass.py to /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/testplugpass.py\n[2024-11-14 06:47:13,039] DEBUG: InstInfo(testplugpass, /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass, None, testplugpass.py, requirements.txt, source/testplugpass)\n[2024-11-14 06:47:20,508] DEBUG: configuring a python virtual environment (pip) in /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/.venv\n[2024-11-14 06:47:20,508] DEBUG: virtual environment created in /tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/.venv.\nCollecting pyln-client\n  Using cached pyln_client-24.8.2-py3-none-any.whl (35 kB)\nCollecting pyln-proto>=23\n  Using cached pyln_proto-24.8.2-py3-none-any.whl (31 kB)\nCollecting pyln-bolt7>=1.0\n  Using cached pyln_bolt7-1.0.246-py3-none-any.whl (18 kB)\nCollecting base58<3.0.0,>=2.1.1\n  Using cached base58-2.1.1-py3-none-any.whl (5.6 kB)\nCollecting cryptography<43,>=42\n  Using cached cryptography-42.0.8-cp37-abi3-manylinux_2_28_x86_64.whl (3.9 MB)\nCollecting bitstring<5.0.0,>=4.1.0\n  Using cached bitstring-4.2.3-py3-none-any.whl (71 kB)\nCollecting coincurve<21,>=20\n  Using cached coincurve-20.0.0-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (1.2 MB)\nCollecting PySocks<2,>=1\n  Using cached PySocks-1.7.1-py3-none-any.whl (16 kB)\nCollecting bitarray<3.0.0,>=2.9.0\n  Using cached bitarray-2.9.3-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (288 kB)\nCollecting cffi>=1.3.0\n  Using cached cffi-1.17.1-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (446 kB)\nCollecting asn1crypto\n  Using cached asn1crypto-1.5.1-py2.py3-none-any.whl (105 kB)\nCollecting pycparser\n  Using cached pycparser-2.22-py3-none-any.whl (117 kB)\nInstalling collected packages: bitarray, asn1crypto, PySocks, pyln-bolt7, pycparser, bitstring, base58, cffi, cryptography, coincurve, pyln-proto, pyln-client\nSuccessfully installed PySocks-1.7.1 asn1crypto-1.5.1 base58-2.1.1 bitarray-2.9.3 bitstring-4.2.3 cffi-1.17.1 coincurve-20.0.0 cryptography-42.0.8 pycparser-2.22 pyln-bolt7-1.0.246 pyln-client-24.8.2 pyln-proto-24.8.2\ndependencies installed successfully\n[2024-11-14 06:47:37,424] DEBUG: virtual environment for cloned plugin: .venv\n[2024-11-14 06:47:37,746] DEBUG: plugin testing error:\n[2024-11-14 06:47:37,746] DEBUG:   Traceback (most recent call last):\n[2024-11-14 06:47:37,746] DEBUG:     File "/tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/testplugpass.py", line 9, in <module>\n[2024-11-14 06:47:37,746] DEBUG:       runpy.run_module("testplugpass", {}, "__main__")\n[2024-11-14 06:47:37,746] DEBUG:     File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/runpy.py", line 210, in run_module\n[2024-11-14 06:47:37,746] DEBUG:       return _run_code(code, {}, init_globals, run_name, mod_spec)\n[2024-11-14 06:47:37,746] DEBUG:     File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/runpy.py", line 87, in _run_code\n[2024-11-14 06:47:37,746] DEBUG:       exec(code, run_globals)\n[2024-11-14 06:47:37,746] DEBUG:     File "/tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/source/testplugpass/testplugpass.py", line 25, in <module>\n[2024-11-14 06:47:37,746] DEBUG:       plugin.run()\n[2024-11-14 06:47:37,746] DEBUG:     File "/tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/.venv/lib/python3.8/site-packages/pyln/client/plugin.py", line 877, in run\n[2024-11-14 06:47:37,747] DEBUG:       return self.print_usage()\n[2024-11-14 06:47:37,747] DEBUG:     File "/tmp/ltests-chy6ayqu/test_local_dir_install_2/lightning-1/reckless/testplugpass/.venv/lib/python3.8/site-packages/pyln/client/plugin.py", line 831, in print_usage\n[2024-11-14 06:47:37,747] DEBUG:       doc = method.long_desc if method.long_desc is not None else "No documentation found"\n[2024-11-14 06:47:37,747] DEBUG:   AttributeError: \'Method\' object has no attribute \'long_desc\'\n[2024-11-14 06:47:37,747] ERROR: plugin testing failed\n[2024-11-14 06:47:37,937] WARNING: testplugpass: installation aborted\n'
```

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/data/recklessrepo/lightningd/testplugpass/requirements.txt

@@ -1,2 +1,2 @@
-pyln-client
+pyln-client>=24.8.2