Update actions/checkout to 6.0.2

Issue gh-18648

Signed-off-by: Josh Cummings <3627351+jzheaux@users.noreply.github.com>

Author: jzheaux

.github/workflows/deploy-docs.yml

@@ -17,7 +17,7 @@ jobs:
     if: github.repository_owner == 'spring-projects'
     steps:
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       with:
         ref: docs-build
         fetch-depth: 1

.github/workflows/gradle-wrapper-upgrade-execution.yml

@@ -19,7 +19,7 @@ jobs:
           git config --global user.name 'github-actions[bot]'
           git config --global user.email 'github-actions[bot]@users.noreply.github.com'
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up JDK 17
         uses: actions/setup-java@v4
         with:

.github/workflows/pr-build-workflow.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository == 'spring-projects/spring-security' }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up gradle
         uses: spring-io/spring-gradle-build-action@v2
         with:
@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository == 'spring-projects/spring-security' }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up gradle
         uses: spring-io/spring-gradle-build-action@v2
         with:

.github/workflows/release-scheduler.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       with:
         fetch-depth: 1
     - name: Dispatch