ci: check generated checksums.txt

Author: jjyr

.github/workflows/checksum.yaml

@@ -20,5 +20,5 @@ jobs:
       run: make docker-build
     - name: Checksum binaries
       run: sha256sum -c ci-expected-checksums.txt
-
-
+    - name: Check checksums.txt
+      run: diff checksums.txt ci-expected-checksums.txt