The GraalVM check fails to run on a release branch

https://github.com/googleapis/google-cloud-java/pull/11494#issuecomment-2729902403

```
fatal: ambiguous argument '1.52.x...01db2d790e153822886b5e7e6e9ddf16c08443ce': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git  [...] -- [...]'
```