ci: bump the ci group with 4 updates

Bumps the ci group with 4 updates: [actions/checkout](https://github.com/actions/checkout), [actions/upload-artifact](https://github.com/actions/upload-artifact), [actions/setup-python](https://github.com/actions/setup-python) and [actions/download-artifact](https://github.com/actions/download-artifact).


Updates `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)

Updates `actions/upload-artifact` from 4 to 5
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v5)

Updates `actions/setup-python` from 5 to 6
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v5...v6)

Updates `actions/download-artifact` from 5 to 6
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: ci
- dependency-name: actions/upload-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: ci
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: ci
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: ci
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ${{matrix.os}}
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up MSVC [Windows]
         if: matrix.os == 'windows-latest'

.github/workflows/docs.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install Doxygen
         uses: ssciwr/doxygen-install@v1

.github/workflows/release.yml

@@ -23,7 +23,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up MSVC [Windows]
         if: matrix.os == 'windows-latest'
@@ -36,7 +36,7 @@ jobs:
         run: cmake --build build --config Release
 
       - name: Upload Artifact (C++)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: cpp-dist-${{matrix.os}}
           path: |
@@ -51,7 +51,7 @@ jobs:
         run: cmake --build build --config Release
 
       - name: Upload Artifact (C)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: c-dist-${{matrix.os}}
           path: |
@@ -69,7 +69,7 @@ jobs:
         working-directory: '${{github.workspace}}/lang/python'
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Configure CMake
         working-directory: '${{github.workspace}}'
@@ -84,7 +84,7 @@ jobs:
           pipx run twine check dist/*
 
       - name: Upload Artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: python-dist-sdist
           path: '${{github.workspace}}/lang/python/dist/*.tar.gz'
@@ -101,10 +101,10 @@ jobs:
         os: [ubuntu-latest, windows-latest]
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.13'
 
@@ -118,7 +118,7 @@ jobs:
           python -m cibuildwheel --output-dir dist
 
       - name: Upload Artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: python-dist-bdist-${{matrix.os}}
           path: '${{github.workspace}}/lang/python/dist/*.whl'
@@ -137,7 +137,7 @@ jobs:
       id-token: write
     steps:
       - name: Download Wheels
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           pattern: python-dist-*
           path: dist
@@ -158,7 +158,7 @@ jobs:
       contents: write
     steps:
       - name: Download Artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           pattern: '*-dist-*'
           path: dist/