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/ble-test.yml

@@ -40,7 +40,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v7
       - name: Cache west modules
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         env:
           cache-name: cache-zephyr-modules
         with:

.github/workflows/build-user-config.yml

@@ -108,7 +108,7 @@ jobs:
           fi
 
       - name: Cache west modules
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         continue-on-error: true
         env:
           cache_name: cache-zephyr-${{ env.zephyr_version }}-modules

.github/workflows/build.yml

@@ -34,7 +34,7 @@ jobs:
         with:
           persist-credentials: false
       - name: Cache west modules
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         env:
           cache-name: cache-zephyr-modules
         with:

.github/workflows/test.yml

@@ -42,7 +42,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v7
       - name: Cache west modules
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         env:
           cache-name: cache-zephyr-modules
         with: