Update c-cpp.yml

Tested action with erroneous input

Author: CowFreedom

.github/workflows/c-cpp.yml

@@ -18,4 +18,4 @@ jobs:
       - name: Generate artifact attestation
         uses: actions/attest-build-provenance@v2
         with:
-          subject-path: 'build/dotprod_exe'
+          subject-path: 'build/nothing'