Propagate duckdb commit and version to Java.yml

[smvv]

Context

This PR is part of the alpha release versions initiative.

The added action sends the release state of the python client back to the release event system.

See also the release event system usage.

Changes

I had to make some CI changes so we can propagate workflow_dispatch values to the CI run.

The flow is now:

1. duckdb core sends core_ready to Release event system.
2. Release event system sends a dispatch event to duckdb/duckdb-java/Vendor.yml
3. Vendor dispatches Java.yml with the required input parameters.
4. Vendor.yml sends client_ready back to Release event system.

Without the CI job/workflow restructuring, the values for duckdb_version and duckdb_commit were lost when we want to send the client_ready back.

[smvv]

note: we're filtering on the head_ref (= vendoring-*) instead of the base_ref (= main), so pull_request.branch-ignores does not work, unfortunately.