Use specific WT versions to resolve possible django compability issues

Author: marteinn

.github/workflows/main.yml

@@ -8,10 +8,7 @@ jobs:
     strategy:
       matrix:
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
-        wagtail-version:
-        - 6.3
-        - 7.0
-        - 7.1
+        wagtail-version: ["6.3.5", "7.0.2", "7.1"]
     steps:
     - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}