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

Bumps [actions/cache](https://github.com/actions/cache) from 5 to 6.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/actions/cache/compare/v5...v6)

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

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

.github/workflows/docs.yaml

@@ -48,7 +48,7 @@ jobs:
         run: "cd docs && [[ -f package-lock.json || -f npm-shrinkwrap.json ]] && npm ci || true"
       - name: Cache Restore
         id: cache-restore
-        uses: actions/cache/restore@v5
+        uses: actions/cache/restore@v6
         with:
           path: |
             ${{ runner.temp }}/hugo_cache
@@ -64,7 +64,7 @@ jobs:
             --cacheDir "${{ runner.temp }}/hugo_cache"
       - name: Cache Save
         id: cache-save
-        uses: actions/cache/save@v5
+        uses: actions/cache/save@v6
         with:
           path: |
             ${{ runner.temp }}/hugo_cache

.github/workflows/linutil.yml

@@ -21,14 +21,14 @@ jobs:
         run: sudo apt-get update && sudo apt-get install musl-tools
         
       - name: Cache Cargo registry
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/.cargo/registry
           key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
           restore-keys: ${{ runner.os }}-cargo-registry-
 
       - name: Cache Cargo index
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/.cargo/git
           key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}

.github/workflows/rust.yml

@@ -27,14 +27,14 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo registry
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/.cargo/registry
           key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
           restore-keys: ${{ runner.os }}-cargo-registry-
 
       - name: Cache Cargo index
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/.cargo/git
           key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}