Upgrade docker image & clang-format

• Docker image updated to Ubuntu 22.04LTS
• Clang-format is now clang-format-14 (the default version from Ubuntu 22.04). With this new version, lambdas are sometimes badly indented => this has been fixed.

.gitlab-ci.yml

@@ -26,7 +26,7 @@ format:
     <<: *global_tag_def
     stage: build
     script:
-        - clang-format --version # we use clang-format-10 exclusively
+        - clang-format --version # we use clang-format-14 exclusively
         - ./ext/amfe/scripts/format_code.py
         - mkdir -p patches
         - if git diff --patch --exit-code > patches/clang-format.patch; then echo "Clang format changed nothing"; else echo "Clang format found changes to make!"; false; fi