* Use git submodules for (securely) using third party Github Actions
List of repositories added as submodules:
EndBug/latest-tag@latest
morrisoncole/pr-lint-action@v1.4.1
trilom/file-changes-action@v1.2.4
styfle/cancel-workflow-action@0.6.0
apache-superset/cached-dependencies@b90713b
unsplash/comment-on-pr@v1.2.0
* build: inline cached-dependencies to unblock CI
* Run E2E on pull_request on;y
* Inline all external actions
* Checkout needed for internal actions
Also fixes pre-commit
* Add missing files