Amend latest commit instead of creating a new one

The version's patch number equals the commit count. Creating a new
commit changes that count, causing invoke setver to find another
version bump on the next CD run — an infinite loop.

Amending the triggering commit keeps the count unchanged, so the
subsequent CD run finds no version change and stops. Force push is
needed because the amended SHA differs from origin, but is safe here
since allow_force_pushes is enabled and TEAM4-0 has the ruleset
admin bypass.

Author: CasperWA

.github/workflows/cd_release.yml

@@ -71,11 +71,11 @@ jobs:
       if: steps.update_version_step.outputs.continue_workflow == 'true'
       run: |
         git add app/__init__.py CHANGELOG.md
-        git commit -m "[bot] Update version and CHANGELOG"
+        git commit --amend --no-edit
 
     - name: Update '${{ env.DEFAULT_REPO_BRANCH }}'
       if: steps.update_version_step.outputs.continue_workflow == 'true'
-      run: git push origin ${{ env.DEFAULT_REPO_BRANCH }}
+      run: git push --force origin ${{ env.DEFAULT_REPO_BRANCH }}
 
   publish_container_image:
     name: Publish Container image on GH Packages