ci: Pin Python, Fedora and Ubuntu runner versions.

We initially thought always using the latest releases would be more
maintainable because we didn't have to bump versions manually.  It turns
out that it's the opposite, CI suddenly starts to fail on versions where
it used to pass.

To avoid ever changing tools in our CI due to newer releases of
Python/Fedora/Ubuntu.  We can always bump versions manually.

Fixes: 5ee07b3 ("ci: Change all GitHub CI jobs to use ubuntu-latest.")
Fixes: 60a53ab ("ci: Add automation for building the containers")
Signed-off-by: Dumitru Ceara <dceara@redhat.com>
Acked-by: Ales Musil <amusil@redhat.com>
Acked-by: Mark Michelson <mmichels@redhat.com>
(cherry picked from commit 278e0d3)

.github/workflows/test.yml

@@ -106,7 +106,7 @@ jobs:
     - name: set up python
       uses: actions/setup-python@v4
       with:
-        python-version: '3.x'
+        python-version: '3.11'
 
     - name: prepare
       run:  ./.ci/linux-prepare.sh
@@ -175,7 +175,7 @@ jobs:
     - name: set up python
       uses: actions/setup-python@v4
       with:
-        python-version: '3.x'
+        python-version: '3.11'
     - name: prepare
       run:  ./.ci/osx-prepare.sh
     - name: build