fix: handle unknown specification kinds

[Devansh-567]

Summary

bin/annotate-specification-links currently looks up URL templates using version_urls[kind]. If kind is not present in specification_urls.json, this raises a KeyError before the subsequent None check can run, making the intended error-handling path unreachable.

This change replaces the dictionary indexing with version_urls.get(kind), allowing unknown specification kinds to be handled gracefully by emitting the existing annotation instead of terminating the script with a traceback.

Changes

• Replace version_urls[kind] with version_urls.get(kind) in bin/annotate-specification-links.

Why

The code already contains logic to handle missing URL templates:

url_template = version_urls.get(kind)
if url_template is None:
    ...