chore: use only node 14

Author: mportuga

.github/workflows/pull_request.yml

@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [14.x, 16.x, 18.x]
+        node-version: [14.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps: