feat: add release-please action

[dsotirakis]

This PR is responsible for adding the googleapis/release-please-action. This action is used to make a shared-workflows repo release and tag.
Releasing and tagging this repo will help add automations around updating the commit hashes of the teams/individuals who use the workflows.

First tag and release: https://github.com/grafana/shared-workflows/releases/tag/v1.0.0
Changelog: https://github.com/grafana/shared-workflows/blob/main/CHANGELOG.md

Notice that there are 3 tags, v1, v1.0 and v1.0.0. This happens because there are users who prefer to use either a major, minor or a patch version of any given workflow. We create all three of them in order to make it able for the user to get all the changes without pinning their versions.

Note:

In order for release-please-action to work, the PRs need to follow the conventional commits specification, thus we now use the lint-pr-title action for pull requests in this repo.

[iainlane]

just looking at the docs (interesting project, haven't seen it before)... should we use a manifest? mentions it's for monorepos - maybe we could release the stuff separately then?

[dsotirakis]

just looking at the docs (interesting project, haven't seen it before)... should we use a manifest? mentions it's for monorepos - maybe we could release the stuff separately then?

wanted to make it as simple as possible to begin with, I think the manifest is great but overpowered 😁
will have a look anyway.

[iainlane]

just looking at the docs (interesting project, haven't seen it before)... should we use a manifest? mentions it's for monorepos - maybe we could release the stuff separately then?

wanted to make it as simple as possible to begin with, I think the manifest is great but overpowered 😁 will have a look anyway.

ah yeah, the main thing I'm thinking is that when we make releases it should result in Dependabot PRs to people who use our actions, and creating those when there aren't actual changes to deploy... is not that friendly

[iainlane]

We could have a play with the single-release thing and add a manifest later if you want?