chore: check if CI works on node 12

Author: woothu

.github/workflows/project-check.yml

@@ -11,7 +11,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [8.x, 10.x, 12.x]
+        node-version: [12.x]
         os: [ubuntu-latest, windows-latest, macOS-latest]
 
     steps: