Update actions/checkout action to v3 (#327)

Signed-off-by: Renovate Bot <bot@renovateapp.com>

Author: renovate[bot]

.github/workflows/lint-test.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           fetch-depth: 0
 

.github/workflows/renovate-config-validator.yml

@@ -11,6 +11,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: Validate
         uses: rinchsan/renovate-config-validator@v0.0.10