Monorepo release workflows should normalize subdir/vX.Y.Z tags for cross-language publishing

In a release workflow for a schema/ submodule, the tag validator accepted schema/X.Y.Z but rejected schema/vX.Y.Z. Go module tags for subdirectory modules are typically subdir/vX.Y.Z, so rejecting the v prefix can block proper Go semver tags. The safe pattern is to accept optional v after the subdir prefix and normalize to a PEP 440 version (without leading v) for Python package metadata updates.

For monorepos releasing a Go submodule and a Python package from the same tag, accept tags of the form subdir/vX.Y.Z in CI, then strip both the subdir/ prefix and optional leading v before writing the Python package version.