build: keep bun.lock as the only lockfile

CI installs with bun. The pnpm lockfile goes, as does a workspace
file holding only unfilled allowBuilds placeholders.

Author: TheGreatAxios

package.json

@@ -9,6 +9,7 @@
     "bun": ">=1.2.0"
   },
   "type": "module",
+  "packageManager": "bun@1.4.0",
   "sideEffects": [
     "**/*.css"
   ],