tree-sitter-groovy exposes inheritance via the same `superclass` and
`interfaces`/`type_list` fields as tree-sitter-java, but the inheritance-
emitting block in `_extract_generic` was gated on
`ts_module == "tree_sitter_java"`. Groovy was the only class-based JVM
language in the file with no inheritance handler, so every Groovy
`extends`/`implements` was silently dropped (contains/methods/imports/calls
were unaffected).
Widen the gate to include `tree_sitter_groovy`; the existing
`_emit_java_parent_type` path handles the identical node shapes verbatim.
Adds a base class + interface to the Groovy fixture and two regression
tests (extends -> inherits, implements -> implements).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>