Support schedule triggers for Dart (Cloud Run) functions

[Ortes]

Description

Deploying a Dart function that uses firebase.scheduler.onSchedule fails: setTrigger() and deleteTrigger() throw Schedule triggers for Cloud Run functions are not supported yet. for platform: "run". The Cloud Run service is created first, so the deploy leaves a service with no Cloud Scheduler job.

This PR reuses the existing GCFv2 schedule path, since cloudscheduler.jobFromEndpoint() already handles run (HTTP target on endpoint.uri with an OIDC token):

• setTrigger / deleteTrigger: run goes through upsertScheduleV2 / deleteScheduleV2.
• createRunFunction / updateRunFunction: grant roles/run.invoker to the scheduler's service account (the endpoint's serviceAccount, else the default compute SA), as createV2Function / updateV2Function already do.
• runv2.serviceFromEndpoint / endpointFromService: persist scheduleTrigger in the firebase-functions-metadata annotation. Without it, the existing service is read back as httpsTrigger, and the second deploy aborts with Changing from an HTTPS function to a scheduled function is not allowed.

Related: #10851 does the same for Firestore event triggers on Cloud Run. The two are independent; this one only touches schedule triggers.

Scenarios Tested

Unit tests added in fabricator.spec.ts and runv2.spec.ts.

Manually on a real project (europe-west3), with a Dart onSchedule(schedule: '*/2 * * * *') using timeZone and retryConfig:

• First deploy creates the Cloud Run service, the Cloud Scheduler job (correct schedule, time zone, retry count, OIDC service account) and the run.invoker binding.
• The job fires on schedule and on gcloud scheduler jobs run; the handler gets a 200 and the ScheduledEvent headers.
• A second deploy with no change updates the service without the HTTPS-to-scheduled abort.
• Changing timeZone / retryCount updates the job in place.
• A throwing handler returns 500 and Cloud Scheduler retries exactly retryCount times.
• Unauthenticated requests to the service URL get 403.
• Removing the function from the codebase (and functions:delete) deletes both the service and the job.

Sample Commands

FIREBASE_CLI_EXPERIMENTS=dartfunctions firebase deploy --only functions

[gemini-code-assist]

Code Review

This pull request introduces support for deploying scheduled Dart functions (onSchedule) to Cloud Run. Key changes include updating the fabricator to manage schedule triggers and configure the run.invoker role for the scheduler's service account, as well as preserving schedule trigger metadata in Cloud Run service annotations for backend reconstruction. Corresponding unit tests and a changelog entry have been added. I have no feedback to provide as there are no review comments.