Bump actions/checkout from 2 to 3.1.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.1.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v3.1.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3.1.0
 
       - name: Setup Java ${{ matrix.jdk-version }}
         uses: actions/setup-java@v3
@@ -57,13 +57,13 @@ jobs:
           ./gradlew --info publishToMavenLocal --warning-mode all
 
       - name: Clone dgs-examples-java
-        uses: actions/checkout@master
+        uses: actions/checkout@v3.1.0
         with:
           repository: Netflix/dgs-examples-java
           path: build/examples/dgs-examples-java
 
       - name: Clone dgs-examples-kotlin
-        uses: actions/checkout@master
+        uses: actions/checkout@v3.1.0
         with:
           repository: Netflix/dgs-examples-kotlin
           path: build/examples/dgs-examples-kotlin

.github/workflows/nebula-publish.yml

@@ -9,7 +9,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v3.1.0
       - name: Setup jdk 8
         uses: actions/setup-java@v3
         with:

.github/workflows/update-gradle-wrapper.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3.1.0
       - name: Set up JDK 1.8
         uses: actions/setup-java@v3
         with: