chore: bump the actions group with 2 updates

Bumps the actions group with 2 updates: [actions/cache](https://github.com/actions/cache) and [actions/upload-artifact](https://github.com/actions/upload-artifact).


Updates `actions/cache` from 4 to 5
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4...v5)

Updates `actions/upload-artifact` from 5.0.0 to 6.0.0
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@330a01c...b7c566a)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/upload-artifact
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

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

Author: dependabot[bot]

.github/workflows/build-book.yml

@@ -38,7 +38,7 @@ jobs:
         run: echo "::set-output name=dir::$(pip cache dir)"
 
       - name: Cache dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ steps.pip-cache.outputs.dir }}
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
@@ -53,7 +53,7 @@ jobs:
 
       # Save html as artifact
       - name: Save book html as artifact for viewing
-        uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
         with:
           name: book-html
           path: |