Pin dependency benchmark to 2.1.4

Author: renovate[bot]

package.json

@@ -29,7 +29,7 @@
   "devDependencies": {
     "@types/parse5": "6.0.1",
     "ava": "3.15.0",
-    "benchmark": "^2.1.4",
+    "benchmark": "2.1.4",
     "esbuild": "0.13.3",
     "globby": "12.0.2",
     "np": "7.5.0",