fix(gce_provision): move to latest scylla==4.6.3
fix(gce_provision): move to latest scylla==4.6.3

Since there a new java security fix, that breaks nodetool in
older scylla versions, we should be move to lastest release.

```
nodetool: Failed to connect to '127.0.0.1:7199' - URISyntaxException:
'Malformed IPv6 address at index 7: rmi://[127.0.0.1]:7199'.
```

scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests