Replace pytest/tox test suite with BATS

The Python-based test infrastructure (pytest, tox, testinfra) is replaced
with BATS (Bash Automated Testing System), matching the approach already
used in FTL

Changes:
- Add test/run.sh — single entry point replacing all 15 tox.*.ini files;
  accepts DISTRO env var, builds the test image, installs BATS on demand,
  and selects test files based on distro family (debian/alpine/rhel)
- Add test/helpers/mocks.bash — bash equivalents of conftest.py's
  mock_command*, mock_command_2, and mock_command_passthrough helpers;
  uses base64 transfer to write mock scripts into containers safely
- Add test/test_automated_install.bats — replaces test_any_automated_install.py
- Add test/test_utils.bats — replaces test_any_utils.py
- Add test/test_selinux.bats — replaces test_centos_fedora_common_support.py;
  only run on CentOS/Fedora (rhel family)
- Remove conftest.py, requirements.txt, setup.py, __init__.py
- Remove all 15 tox.*.ini files
- Remove all three Python test files
- Update .github/workflows/test.yml: drop Python setup, tox invocation,
  and black formatting check; distro-test job now runs bash test/run.sh
- Update .gitignore: remove Python-specific entries, add test/libs/

Signed-off-by: PromoFaux <PromoFaux@users.noreply.github.com>
Signed-off-by: Adam Warner <me@adamwarner.co.uk>

.github/workflows/test.yml

@@ -7,11 +7,6 @@ on:
 permissions:
   contents: read
 
-env:
-  FORCE_COLOR: 1
-  PYTHONUNBUFFERED: 1
-  PYTHONUTF8: 1
-
 jobs:
   smoke-tests:
     if: github.event.pull_request.draft == false
@@ -25,18 +20,18 @@ jobs:
       - name: Check scripts in repository are executable
         run: |
           IFS=$'\n';
-          for f in $(find . -name '*.sh'); do if [[ ! -x $f ]]; then echo "$f is not executable" && FAIL=1; fi ;done
+          for f in $(find . -name '*.sh' -o -name '*.bats'); do if [[ ! -x $f ]]; then echo "$f is not executable" && FAIL=1; fi ;done
           unset IFS;
           # If FAIL is 1 then we fail.
           [[ $FAIL == 1 ]] && exit 1 || echo "Scripts are executable!"
 
       - name: Differential ShellCheck
+        if: github.event_name == 'pull_request'
         uses: redhat-plumbers-in-action/differential-shellcheck@d965e66ec0b3b2f821f75c8eff9b12442d9a7d1e #v5.5.6
         with:
           severity: warning
           display-engine: sarif-fmt
 
-
       - name: Spell-Checking
         uses: codespell-project/actions-codespell@8f01853be192eb0f849a5c7d721450e7a467c579 #v2.2
         with:
@@ -48,12 +43,6 @@ jobs:
       - name: Run editorconfig-checker
         run: editorconfig-checker
 
-      - name: Check python code formatting with black
-        uses: psf/black@c6755bb741b6481d6b3d3bb563c83fa060db96c9 #26.3.1
-        with:
-          src: "./test"
-          options: "--check --diff --color"
-
   distro-test:
     if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
@@ -79,22 +68,9 @@ jobs:
             alpine_3_22,
             alpine_3_23,
           ]
-    env:
-      DISTRO: ${{matrix.distro}}
     steps:
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
 
-      - name: Set up Python
-        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 #v6.2.0
-        with:
-          python-version: "3.13"
-
-      - name: Install wheel
-        run:  pip install wheel
-
-      - name: Install dependencies
-        run: pip install -r test/requirements.txt
-
-      - name: Test with tox
-        run: tox -c test/tox.${DISTRO}.ini
+      - name: Run BATS test suite for ${{ matrix.distro }}
+        run: DISTRO=${{ matrix.distro }} bash test/run.sh