Add locheck run script to Riot target. (#6069)

* Add a locheck pre-build step to find all .strings errors.
* Treat locheck warnings as errors.
* Install mint on CI and pin locheck version.
* Clean up localised strings with invalid formatting

.github/workflows/release-alpha.yml

@@ -63,11 +63,12 @@ jobs:
 
       # Common setup
       # Note: GH actions do not support yaml anchor yet. We need to duplicate this for every job
+      - name: Brew bundle
+        run: brew bundle
       - name: Bundle install
         run: |
           bundle config path vendor/bundle
           bundle install --jobs 4 --retry 3
-
       - name: Use right MatrixSDK versions
         run: bundle exec fastlane point_dependencies_to_related_branches