Resolve conflicts automatically when making new release

[vaadin-miki]

During automated release process some files are modified, which causes conflicts when creating a new release.

Find a way to automatically accept changes from the incoming (release) branch when making a PR to master.

[vaadin-miki]

release notes must be updated separately to development before the release-X.Y.Z branch gets created

so the workflow should be: close milestone -> make branch for release notes -> make release notes -> make pr to development -> accept PR -> create release-X.Y.Z branch -> update versions in that branch -> merge master into that branch, using --strategy=ours -> create PR from release-X.Y.Z into master

[vaadin-miki]

alrighty, more additional steps: since development is protected by checks, a PR must be made for release notes separately, and ideally there is another workflow fired when that PR is ready to be closed and closes it

[vaadin-miki]

this is great... according to the docs and support check_suite events are not triggered from the default actions workflow, which means on: status events should be used

https://github.uint.cloudmunity/t/on-check-suite-never-triggers-why/17303/6