chore(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v4...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/classic-autogpt-ci.yml

@@ -61,7 +61,7 @@ jobs:
       #   See: https://github.com/actions/runner/issues/598#issuecomment-2011890429
 
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           submodules: true

.github/workflows/classic-autogpt-docker-cache-clean.yml

@@ -16,7 +16,7 @@ jobs:
         build-type: [release, dev]
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3

.github/workflows/classic-autogpt-docker-ci.yml

@@ -35,7 +35,7 @@ jobs:
         build-type: [release, dev]
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -101,7 +101,7 @@ jobs:
 
     steps:
       - name: Check out repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           submodules: true
 

.github/workflows/classic-autogpt-docker-release.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Log in to Docker hub
         uses: docker/login-action@v3

.github/workflows/classic-autogpts-ci.yml

@@ -44,7 +44,7 @@ jobs:
       min-python-version: '3.10'
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           submodules: true

.github/workflows/classic-benchmark-ci.yml

@@ -42,7 +42,7 @@ jobs:
         working-directory: classic/benchmark
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           submodules: true
@@ -114,7 +114,7 @@ jobs:
     timeout-minutes: 20
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           submodules: true

.github/workflows/classic-benchmark_publish_package.yml

@@ -10,7 +10,7 @@ jobs:
       contents: write
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         submodules: true
         fetch-depth: 0

.github/workflows/classic-forge-ci.yml

@@ -63,7 +63,7 @@ jobs:
       #   See: https://github.com/actions/runner/issues/598#issuecomment-2011890429
 
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           submodules: true

.github/workflows/classic-frontend-ci.yml

@@ -25,7 +25,7 @@ jobs:
 
     steps:
       - name: Checkout Repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Flutter
         uses: subosito/flutter-action@v2

.github/workflows/classic-python-checks.yml

@@ -33,7 +33,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - id: changes-in
         name: Determine affected subprojects
@@ -68,7 +68,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -120,7 +120,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/pr-overlap-check.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0  # Need full history for merge testing