Be less verbose

The output is already printed once anyway.

```git-check-assertions
[success] ./test/git-check-assertions.bats
```

bin/git-check-assertions

@@ -135,7 +135,6 @@ for commit_hash in "${commits[@]}"; do
 			    for expected in step["assertions"]:
 			        if expected not in output:
 			            print(f"Expected output to contain: {expected}")
-			            print(f"Actual output: {output}")
 			            sys.exit(1)
 			EOF
     }