fix env variable name

Author: nirinchev

.github/workflows/check-test.yaml

@@ -109,4 +109,4 @@ jobs:
         env:
           COVERALLS_GIT_BRANCH: ${{ github.head_ref || github.ref_name }}
           COVERALLS_REPO_TOKEN: ${{ github.token }}
-          COVERALLS_COMMIT: ${{ github.event.pull_request.head.sha || github.sha }}
+          COVERALLS_GIT_COMMIT: ${{ github.event.pull_request.head.sha || github.sha }}