Bump tox from 4.18.0 to 4.20.0

Bumps [tox](https://github.com/tox-dev/tox) from 4.18.0 to 4.20.0.
- [Release notes](https://github.com/tox-dev/tox/releases)
- [Changelog](https://github.com/tox-dev/tox/blob/main/docs/changelog.rst)
- [Commits](tox-dev/tox@4.18.0...4.20.0)

---
updated-dependencies:
- dependency-name: tox
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

CI/requirements_ci.in

@@ -2,4 +2,4 @@ bump-my-version==0.26.0
 coveralls==4.0.1
 pip==24.2.0
 flit==3.9.0
-tox==4.18.0
+tox==4.20.0

CI/requirements_ci.txt

@@ -16,9 +16,9 @@ bump-my-version==0.26.0 \
     --hash=sha256:9e2c01b7639960379440c4a371b3c8c0aa66cf6979985f1c9ba2e7c2fb4a185f \
     --hash=sha256:fe35ebae91e92deebe809ce06bfa37303e45e4f087ad4a371f605702e767623f
     # via -r CI/requirements_ci.in
-cachetools==5.4.0 \
-    --hash=sha256:3ae3b49a3d5e28a77a0be2b37dbcb89005058959cb2323858c2657c4a8cab474 \
-    --hash=sha256:b8adc2e7c07f105ced7bc56dbb6dfbe7c4a00acce20e2227b3f355be89bc6827
+cachetools==5.5.0 \
+    --hash=sha256:02134e8439cdc2ffb62023ce1debca2944c3f289d66bb17ead3ab3dede74b292 \
+    --hash=sha256:2cc24fb4cbe39633fb7badd9db9ca6295d766d9c2995f245725a46715d050f2a
     # via tox
 certifi==2024.7.4 \
     --hash=sha256:5a1e7645bc0ec61a09e26c36f6106dd4cf40c6db3a1fb6352b0244e7fb057c7b \
@@ -393,9 +393,9 @@ tomlkit==0.13.0 \
     --hash=sha256:08ad192699734149f5b97b45f1f18dad7eb1b6d16bc72ad0c2335772650d7b72 \
     --hash=sha256:7075d3042d03b80f603482d69bf0c8f345c2b30e41699fd8883227f89972b264
     # via bump-my-version
-tox==4.18.0 \
-    --hash=sha256:0a457400cf70615dc0627eb70d293e80cd95d8ce174bb40ac011011f0c03a249 \
-    --hash=sha256:5dfa1cab9f146becd6e351333a82f9e0ade374451630ba65ee54584624c27b58
+tox==4.20.0 \
+    --hash=sha256:21a8005e3d3fe5658a8e36b8ca3ed13a4230429063c5cc2a2fdac6ee5aa0de34 \
+    --hash=sha256:5b78a49b6eaaeab3ae4186415e7c97d524f762ae967c63562687c3e5f0ec23d5
     # via -r CI/requirements_ci.in
 typing-extensions==4.12.2 \
     --hash=sha256:04e5ca0351e0f3f85c6853954072df659d0d13fac324d0072316b67d7794700d \