fix(ci): only report coverage when it isn't coming from fork

Forks can't share their own secrets to upstream. Additionally, upstream
isn't using its own secret when PR is coming from a fork. Skip this step
in this case, instead of failing the PR.

Signed-off-by: Krisztian Szilvasi <34309983+kr-t@users.noreply.github.com>

Author: kr-t

.github/workflows/linux.yml

@@ -74,6 +74,7 @@ jobs:
           path: build/coverage
 
       - name: Report code coverage
+        if: github.event.pull_request.head.repo.full_name == github.repository
         uses: marocchino/sticky-pull-request-comment@v3
         with:
           GITHUB_TOKEN: ${{ secrets.TOKEN_WRITE_PR }}