Add a lint runner using a rocky8 container for realistic env as explained on

https://www.claudiokuenzler.com/blog/1381/how-to-run-github-ci-cd-workflows-actions-rocky-linux

Author: jonasbardino

.github/workflows/python-sanity-check.yml

@@ -46,3 +46,36 @@ jobs:
     #  run: |
     #    pytest
 
+  lint-python2-rocky8:
+    runs-on: ubuntu-22.04
+    container:
+      image: rockylinux/rockylinux:8
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python 2.7 with DNF and link to default
+      run: |
+        sudo dnf install -y python2 python2-pip
+    - name: Install dependencies
+      run: |
+        python2 -m pip install --upgrade pip
+        pip2 install flake8 pytest
+        if [ -f requirements.txt ]; then pip2 install -r requirements.txt; fi
+    - name: Lint with flake8
+      run: |
+        # TODO: fix unittest dir and remove from excludes
+        # TODO: fix or migrate legacy grsfs-fuse dir and remove from excludes
+        # TODO: should tests be included here - currently fail on py3-only FileNotFoundError, etc.
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --exclude=tests,state,envhelp,fixture,output,unittest,grsfs-fuse,irclib.py,seafile-seahub_settings-template.py --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 . --exclude=tests,state,envhelp,fixture,output,unittest,grsfs-fuse,vm-proxy,irclib.py,seafile-seahub_settings-template.py --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+        # NOTE: for interactive clean up one can use current ignores
+        # E501 Ignore long lines, E402 imports below top, E722 bare except,
+        # F401 unused imports, F502 explicit list in str expand, F841 unused var,
+        # E721 compare type instead of isinstance, W293 blank line with space,
+        # C901 too complex get
+        #flake8 mig --exclude=unittest,grsfs-fuse,vm-proxy,irclib.py,seafile-seahub_settings-template.py --ignore=E501,E402,E722,F401,F502,E713,F841,C901 --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+    # TODO: prepare and enable pytest
+    #- name: Test with pytest
+    #  run: |
+    #    pytest