chore(deps): update actions/checkout action to v3 (element-plus#6633)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

Author: renovate[bot]

.github/workflows/size-report.yml

@@ -12,7 +12,7 @@ jobs:
     env:
       CI_JOB_NUMBER: 1
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Setup node
         uses: actions/setup-node@v3