Bump mattnotmitt/doxygen-action from 1.9.5 to 1.9.8

Bumps [mattnotmitt/doxygen-action](https://github.com/mattnotmitt/doxygen-action) from 1.9.5 to 1.9.8.
- [Release notes](https://github.com/mattnotmitt/doxygen-action/releases)
- [Commits](mattnotmitt/doxygen-action@v1.9.5...v1.9.8)

---
updated-dependencies:
- dependency-name: mattnotmitt/doxygen-action
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

.github/workflows/build-sphinx.yml

@@ -135,7 +135,7 @@ jobs:
 
       # https://github.com/marketplace/actions/doxygen-action
       - name: Build backend docs
-        uses: mattnotmitt/[email protected].5
+        uses: mattnotmitt/[email protected].8
         with:
             working-directory: 'dpnp/backend/doc'