patch: quickfix the checksum

Author: renatoaraujo

.github/workflows/release.yaml

@@ -29,7 +29,7 @@ jobs:
         run: ./gradlew shadowJar --no-daemon
 
       - name: Generate Checksum
-        run: sha256sum build/libs/uk-invitation-letter-${{ github.ref_name }}.jar > checksum.txt
+        run: sha256sum build/libs/uk-invitation-letter-${{ github.ref_name }}.jar | awk '{print $1}' > checksum.txt
 
       - uses: marvinpinto/action-automatic-releases@latest
         with: