Use ansible-core from my semantic-markup branch.

Author: felixfontein

.github/workflows/ansible-test.yml

@@ -51,6 +51,15 @@ jobs:
         with:
           ansible-core-version: ${{ matrix.ansible }}
           testing-type: sanity
+        if: matrix.ansible != 'devel'
+
+      - name: Perform sanity testing
+        uses: ansible-community/ansible-test-gh-action@release/v1
+        with:
+          ansible-core-version: semantic-markup
+          ansible-core-github-repository-slug: felixfontein/ansible
+          testing-type: sanity
+        if: matrix.ansible == 'devel'
 
   units:
     # Ansible-test on various stable branches does not yet work well with cgroups v2.