ci: add commitMode github-api to trigger CI on version PR (Fission-AI#477)

* ci: use GitHub App token to trigger CI on version PR

Replace GITHUB_TOKEN with a GitHub App token so that the version PR
can trigger CI workflows. GITHUB_TOKEN cannot trigger workflows by
design (to prevent infinite loops).

Requires APP_ID variable and APP_PRIVATE_KEY secret to be configured.

* ci: upgrade create-github-app-token to v2

* ci: add commitMode github-api to trigger CI on version PR

Author: TabishB

.github/workflows/release-prepare.yml

@@ -50,6 +50,8 @@ jobs:
         with:
           title: 'chore(release): version packages'
           createGithubReleases: true
+          # Use github-api to attribute commits to the GitHub App, enabling CI triggers
+          commitMode: github-api
           # Use CI-specific release script: relies on version PR having been merged
           # so package.json already contains the bumped version.
           publish: pnpm run release:ci