chore(deps): update actions/checkout action to v6

Author: renovate-bot

.github/workflows/check_unexpected_changes.yaml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
     - name: Check out repo
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Generate the JSON Schema
       uses: ./.github/workflows/generate_jsonschema

.github/workflows/generate_jsonschema.yaml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Check out repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Generate the JSON Schema
         uses: ./.github/workflows/generate_jsonschema

.github/workflows/test_clients.yaml

@@ -30,10 +30,10 @@ jobs:
       DOTNET_NOLOGO: true
     steps:
     - name: Proto Schemas > Checkout Repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: .NET Library > Checkout Repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         repository: googleapis/google-cloudevents-dotnet
         path: google-cloudevents-dotnet
@@ -55,13 +55,13 @@ jobs:
       DATA_SOURCE_CHECKOUT_PATH: google-cloudevents
     steps:
       - name: Java Library > Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: googleapis/google-cloudevents-java
           path: ${{ env.LIBRARY_CHECKOUT_PATH }}
 
       - name: Proto Schemas > Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           path: ${{ env.DATA_SOURCE_CHECKOUT_PATH }}
 
@@ -92,13 +92,13 @@ jobs:
 
     steps:
     - name: Go Library > Checkout Repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         repository: googleapis/google-cloudevents-go
         path: ${{ env.LIBRARY_CHECKOUT_PATH }}
 
     - name: Proto Schemas > Checkout Repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         path: ${{ env.DATA_SOURCE_CHECKOUT_PATH }}
 

.github/workflows/test_jsonschemas.yaml

@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
     - name: Check out repo
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Setup Node
       uses: actions/setup-node@v4

.github/workflows/test_proto_syntax.yaml

@@ -27,7 +27,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
     - name: Check out repo
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Test proto syntax via compilation
       run: ./scripts/compile.sh