chore(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -49,7 +49,7 @@ jobs:
         apt-get clean
 
     - name: Checkout PythonQt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Ccache
       uses: hendrikmuhs/[email protected]
@@ -154,7 +154,7 @@ jobs:
         qt5-*-devel
 
     - name: Checkout PythonQt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Build PythonQt (generator_only)
       run: |
@@ -232,7 +232,7 @@ jobs:
         python-version: '${{ matrix.python-version }}'
 
     - name: Checkout PythonQt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Ccache
       uses: hendrikmuhs/[email protected]
@@ -344,7 +344,7 @@ jobs:
     steps:
 
     - name: Checkout PythonQt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Reset PATH
       uses: egor-tensin/cleanup-path@v4

.github/workflows/build_latest.yml

@@ -44,7 +44,7 @@ jobs:
         python-version: '${{ matrix.python-version }}'
 
     - name: Checkout PythonQt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Ccache
       uses: hendrikmuhs/[email protected]

.github/workflows/builddocs.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout main
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install Doxygen
         run: sudo apt-get install doxygen graphviz -y