ci: PR test workflow + lockfile; require node >=20.14

node --test --test-force-exit needs Node 20.14+/22, so the matrix is
[20.x, 22.x] and engines is bumped to match.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

nodejs/package-lock.json

@@ -21,7 +21,7 @@
         "nodemon": "^3.1.11"
       },
       "engines": {
-        "node": ">=18"
+        "node": ">=20.14"
       }
     },
     "node_modules/@redis/bloom": {

nodejs/package.json

@@ -9,7 +9,7 @@
     }
   ],
   "engines": {
-    "node": ">=18"
+    "node": ">=20.14"
   },
   "scripts": {
     "start": "node ./bin/www",