Change fedora-python in action

"Until version 0.4, this action always used the
latest fedora-python-tox image"
https://github.com/fedora-python/tox-github-action

So let's use one that supports python 3.8

Signed-off-by: EstherLerouzic <esther.lerouzic@orange.com>
Change-Id: Ibf3e0baa715da70b4c2af6e2cde6efccfab50311

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
-      - uses: fedora-python/tox-github-action@v0.4
+      - uses: fedora-python/tox-github-action@v37.0
         with:
           tox_env: ${{ matrix.tox_env }}
           dnf_install: ${{ matrix.dnf_install }}