Remove upgrade script

When using the mono repo each module had to check its own dependencies
for upgrades. We have replaced this with Renovate. So this script can be
removed.

package.json

@@ -37,7 +37,6 @@
     "prepublishOnly": "npm run build",
     "eslint-fix": "eslint --ext ts --max-warnings 0 --fix src test",
     "eslint": "eslint --ext ts --max-warnings 0 src test",
-    "upgrade": "npm-check-updates --upgrade",
     "prepare": "husky && node scripts/build.js && cp node_modules/web-tree-sitter/tree-sitter.wasm dist"
   },
   "repository": {