Mark bun.lock as jsonc

Bun added support for a new lockfile format using the jsonc language. It
uses an unconventional file extension, but it would be nice if VSCode
understands it by default anyway.

See https://github.com/oven-sh/bun/pull/15705

extensions/json/package.json

@@ -62,6 +62,7 @@
         ],
         "filenames": [
           "babel.config.json",
+          "bun.lock",
           ".babelrc.json",
           ".ember-cli",
           "typedoc.json"