feat: support for prerelease and prerelease-type (#1101)

[nickreynke]

Add support for prerelease and prerelease-type fields for the newest release-please version.

Closes #1101.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[nickreynke]

Also closes #1178.

[nickreynke]

@ferrarimarco Would you have some time soon to review this PR? :)

[nickreynke]

I tried to fix some problems while using the current version of this PR in a private project of mine. The current version of the project is 0.5.0 (released and present in the .release-please-manifest.json file). When pushing to the develop branch I expected it would create a release-please PR for version 0.6.0-beta but instead created one for 0.6.0. I still can not figure out why...

Here's my release-please.yml GitHub Workflow:

name: Release

on:
  push:
    branches:
      - main
      - develop

permissions:
  contents: write
  pull-requests: write

jobs:
  release-please:
    runs-on: ubuntu-latest
    outputs:
      release_created: ${{ steps.release.outputs.release_created }}
      pr: ${{ steps.release.outputs.pr }}
      tag_name: ${{ steps.release.outputs.tag_name }}
    steps:
      - uses: actions/checkout@v6.0.1

      - uses: nickreynke/release-please-action@3f9a46cb2d21d6f7f9da0f5edb099ab0c076d330
        id: release
        with:
          token: ${{ secrets.RELEASER_PAT }}
          target-branch: ${{ github.ref_name }}
          prerelease: ${{ github.ref_name != 'main' }}
          prerelease-type: 'beta'

My release-please-config.json being the following:

{
  "release-type": "simple",
  "extra-files": [
    "README.md"
  ],
  "packages": {
    ".": {
      "changelog-path": "CHANGELOG.md",
      "release-type": "simple",
      "bump-minor-pre-major": false,
      "bump-patch-for-minor-pre-major": false,
      "draft": false
    }
  },
  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"
}