ci(update-prettier.yml): set version v3 to actions/checkout

Author: gr2m

.github/workflows/update-prettier.yml

@@ -7,7 +7,7 @@ jobs:
   update_prettier:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@v3
       - uses: actions/setup-node@2fddd8803e2f5c9604345a0b591c3020ee971a93 # tag=v3
         with:
           cache: npm