Improve CI image selection. (#536)

.github/workflows/ansible-test.yml

@@ -27,7 +27,15 @@ jobs:
           - '2.9'
           - '2.10'
           - '2.11'
-    runs-on: ubuntu-20.04
+    # Ansible-test on various stable branches does not yet work well with cgroups v2.
+    # Since ubuntu-latest now uses Ubuntu 22.04, we need to fall back to the ubuntu-20.04
+    # image for these stable branches. The list of branches where this is necessary will
+    # shrink over time, check out https://github.com/ansible-collections/news-for-maintainers/issues/28
+    # for the latest list.
+    runs-on: >-
+      ${{ contains(fromJson(
+          '["2.9", "2.10", "2.11", "2.12", "2.13", "2.14"]'
+      ), matrix.ansible) && 'ubuntu-20.04' || 'ubuntu-latest' }}
     steps:
       - name: Perform sanity testing
         uses: felixfontein/ansible-test-gh-action@integration-error-behavior
@@ -38,7 +46,15 @@ jobs:
           testing-type: sanity
 
   units:
-    runs-on: ubuntu-20.04
+    # Ansible-test on various stable branches does not yet work well with cgroups v2.
+    # Since ubuntu-latest now uses Ubuntu 22.04, we need to fall back to the ubuntu-20.04
+    # image for these stable branches. The list of branches where this is necessary will
+    # shrink over time, check out https://github.com/ansible-collections/news-for-maintainers/issues/28
+    # for the latest list.
+    runs-on: >-
+      ${{ contains(fromJson(
+          '["2.9", "2.10", "2.11", "2.12", "2.13", "2.14"]'
+      ), matrix.ansible) && 'ubuntu-20.04' || 'ubuntu-latest' }}
     name: EOL Units (Ⓐ${{ matrix.ansible }})
     strategy:
       # As soon as the first unit test fails, cancel the others to free up the CI queue
@@ -61,7 +77,15 @@ jobs:
           testing-type: units
 
   integration:
-    runs-on: ubuntu-20.04
+    # Ansible-test on various stable branches does not yet work well with cgroups v2.
+    # Since ubuntu-latest now uses Ubuntu 22.04, we need to fall back to the ubuntu-20.04
+    # image for these stable branches. The list of branches where this is necessary will
+    # shrink over time, check out https://github.com/ansible-collections/news-for-maintainers/issues/28
+    # for the latest list.
+    runs-on: >-
+      ${{ contains(fromJson(
+          '["2.9", "2.10", "2.11", "2.12", "2.13", "2.14"]'
+      ), matrix.ansible) && 'ubuntu-20.04' || 'ubuntu-latest' }}
     name: EOL I (Ⓐ${{ matrix.ansible }}+${{ matrix.docker }}+py${{ matrix.python }}:${{ matrix.target }})
     strategy:
       fail-fast: false