fix(gce): make cleanup work correctly
fix(gce): make cleanup work correctly

After the merge of the 'vpc-peering' feature [1] the GCE backend's cleanup
started working incorrectly.
The 'get_security_groups_ips' function, which gets called in the middle
of all the cleanup functions, removes 'NodeType' tag from the shared
dictionary object and it leads to the situation that all of the test run
nodes including SCT runner get deleted as part of the "DB nodes" cleanup.

As a result, the connection to the SCT runner, obviously, gets lost
and job always fails on the "cleanup-resources" stage.

So, fix it by making the mentioned function not change the shared
dictionary object with tags.

[1] https://github.com/scylladb/scylla-cluster-tests/pull/4742

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