roachtest: cluster_creation failed

roachtest.cluster_creation [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyIbmBazel/21244865?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyIbmBazel/21244865?buildTab=artifacts#/failover/partial/lease-gateway) on master @ [5dd5d5a09e7655742e7cb93329bf711c9b2603cb](https://github.com/cockroachdb/cockroach/commits/5dd5d5a09e7655742e7cb93329bf711c9b2603cb):

```
test failover/partial/lease-gateway failed: (test_runner.go:998).func4: in provider: ibm: failed to configure IBM Cloud account: failed to get or create transit gateway: failed to get transit gateways: Too Many Requests [owner=test-eng]
```

Parameters:
- cloud=ibm
- coverageBuild=false
- cpu=2
- diskCount=0
- runtimeAssertionsBuild=false
Help

See: [roachtest README](https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md)

See: [How To Investigate \(internal\)](https://cockroachlabs.atlassian.net/l/c/SSSBr8c7)

/cc @cockroachdb/test-eng

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*cluster_creation.*&sort=title+created&display=lastcommented+project) | [Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-61476

Start with the roachtest README and the linked TeamCity failure artifacts for failover/partial/lease-gateway. Trace the IBM provider setup that gets or creates a transit gateway and investigate the reported Too Many Requests response. Done means the cluster_creation test no longer fails for this condition, with the relevant roachtest behavior covered or documented.

Written by the indexing model from the issue text.