Update WorkManager version to 2.13.0-alpha01

We've snapped the 2.12 release branch, so updating the version on main
to the next alpha version.

Test: PROJECT_PREFIX=:work: ./gradlew checkApi verifyDependencyVersions
Bug: N/A
Change-Id: I5ace3fad99fc8edd05321787e87f48bddf3a4ee9