refactor: maturin.yml

[qjerome]

Summary
Refactor CI workflow to detect tags from git repository and optimize release job execution.

Motivation
The release job previously relied on github.ref to detect tags, which doesn't work when tags are created by other workflows.

Changes

• Add workflow_run trigger to automatically run maturin workflow after weekly PSL update
• Remove if condition from release job that depended on github.ref
• Create separate check-tag job to detect pyfaup-rs-v* tags using git tag --points-at HEAD
• Make check-tag depend on all build jobs (linux, musllinux, windows, macos, sdist)
• Add output to check-tag job indicating if matching tag exists
• Make release job depend on check-tag instead of build jobs
• Add conditional if to release job to only run when tag is present
• Remove redundant conditional checks from release steps

Breaking Changes
None