build(deps): bump openwrt/gh-action-sdk from 5 to 7

Bumps [openwrt/gh-action-sdk](https://github.com/openwrt/gh-action-sdk) from 5 to 7.
- [Commits](openwrt/gh-action-sdk@v5...v7)

---
updated-dependencies:
- dependency-name: openwrt/gh-action-sdk
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/ci.yml

@@ -128,7 +128,7 @@ jobs:
           fetch-depth: 0
 
       - name: Build
-        uses: openwrt/gh-action-sdk@v5
+        uses: openwrt/gh-action-sdk@v7
         env:
           ARCH: ${{ matrix.arch }}
           FEEDNAME: packages_ci