Merge pull request #358 from jcabi/renovate/actions-checkout-4.x

Update actions/checkout action to v4

Author: yegor256

.github/workflows/mvn.yml

@@ -15,7 +15,7 @@ jobs:
         os: [ubuntu-20.04, windows-2022, macos-12]
         java: [11, 17]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions/setup-java@v4
         with:
           distribution: 'temurin'

.github/workflows/xcop.yml

@@ -11,5 +11,5 @@ jobs:
   xcop:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: g4s8/xcop-action@master