Change the release flow to use release branches (#2253)

* What happens if we comment out the runtime crate version from gradle.properties?

* Allow running the release and the CI workflows from an arbitrary commit.

* Does a fake version work?

* Pass `git_ref` from the release workflow.

* It needs to be a valid semver version.

* Sketch new command to upgrade version in gradle.properties

* Command implementation

* Plug the new publisher command into the `release` action.

* Plumb end-to-end

* Fix copyright header.

* Fix lint.

* Temporarily comment out the sanity check.

* Ignore sanity check

* Add a command that prints out the template for CHANGELOG.next.toml

* Add branch check + empty TOML generation.

* Add copyright headers.

* Fix imports.

* Remove sanity check.

* Move script to a file.

* Add a check to validate the tag.

* Remove second build step.

* Move to .github/scripts folder.

* Make the script easier to run locally

* Fail if anything fails.

* Add comment.

* Update .github/scripts/get-or-create-release-branch.sh

Co-authored-by: david-perez <d@vidp.dev>

* Update .github/scripts/get-or-create-release-branch.sh

Co-authored-by: david-perez <d@vidp.dev>

* Update .github/scripts/get-or-create-release-branch.sh

Co-authored-by: david-perez <d@vidp.dev>

* Update .github/workflows/ci.yml

Co-authored-by: david-perez <d@vidp.dev>

* Remove touch.

* Fix indentation and branch name.

* Update .github/workflows/ci.yml

Co-authored-by: david-perez <d@vidp.dev>

* Update .github/workflows/release.yml

Co-authored-by: david-perez <d@vidp.dev>

* Update .github/workflows/release.yml

Co-authored-by: david-perez <d@vidp.dev>

* Explicit flags.

* Use the path that was provided.

* Format

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Co-authored-by: david-perez <d@vidp.dev>