Chore(deps): Bump actions/checkout from 5 to 6 (#980)

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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/publish.yml

@@ -11,7 +11,7 @@ jobs:
     if: github.repository == 'pytest-dev/pytest-html'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
         persist-credentials: false

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
     name: Build Docs
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Set up Python
       uses: actions/setup-python@v6
@@ -37,7 +37,7 @@ jobs:
     name: Build Package
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
         persist-credentials: false
@@ -54,7 +54,7 @@ jobs:
     name: Run javascript unit tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Use Node.js
         uses: actions/setup-node@v6
         with:
@@ -107,7 +107,7 @@ jobs:
       - name: Set newline behavior
         run: git config --global core.autocrlf false
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Use Node.js
         uses: actions/setup-node@v6
@@ -174,7 +174,7 @@ jobs:
       - name: Set newline behavior
         run: git config --global core.autocrlf false
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Start chrome
         run: ./start
@@ -242,7 +242,7 @@ jobs:
       - name: Set newline behavior
         run: git config --global core.autocrlf false
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Start chrome
         run: ./start