GitHub Actions: Add Python 3.14 and 3.14t to the testing

Author: cclauss

.github/workflows/main.yml

@@ -20,6 +20,8 @@ jobs:
           - "3.11"
           - "3.12"
           - "3.13"
+          - "3.14"
+          - "3.14t"
           - "pypy-3.11"
 
     steps:
@@ -39,6 +41,9 @@ jobs:
           uv pip install --system codecov '.[tests]'
           uv pip check
 
+      - if: startsWith(matrix.python-version, '3.14')
+        run: uv pip install --system cryptography>=46.0.3
+
       - name: Allow creation of user namespaces (e.g. to the unshare command)
         run: |
           # .. so that we don't get error: