chore(gitignore): ignore packages/affine-js/deno.lock (sibling rule)

Same pattern as the existing packages/affinescript-cli/deno.lock rule
on the line above: per-package Deno-generated lockfile is artefact,
not source. Running `deno` against packages/affine-js/ otherwise
produces an unstaged deno.lock on every session.

No code change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

.gitignore

@@ -98,6 +98,7 @@ htmlcov/
 # Local-only build workaround (see file header); never committed.
 /dune-workspace
 packages/affinescript-cli/deno.lock
+packages/affine-js/deno.lock
 
 # ADR-015 S3: fetch-pinned WASI adapter (provisioned, not committed)
 tools/vendor/