chore: Update actions/checkout to v6

Author: rmariuzzo

.github/workflows/deploy.yml

@@ -9,7 +9,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v6
 
       - name: Read .nvmrc
         run: echo ::set-output name=NVMRC::$(cat .nvmrc)