roachtest: cluster_creation failed

roachtest.cluster_creation [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/19780251?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/19780251?buildTab=artifacts#/ycsb/D/nodes=3/cpu=32) on release-25.2 @ [cfe971ca2dbac85aed9e65577feab2c87af2bc1d](https://github.com/cockroachdb/cockroach/commits/cfe971ca2dbac85aed9e65577feab2c87af2bc1d):

```
test ycsb/D/nodes=3/cpu=32 failed: (test_runner.go:864).func4: in provider: aws: failed to run: aws ec2 run-instances --associate-public-ip-address --count 1 --instance-type c7gd.8xlarge --image-id ami-05983a09f7dc1c18f --key-name teamcity-runner-htrOtKWj3FzsV9T0dY29GNz1cZA= --region us-east-2 --security-group-ids sg-04d72b57e29d671f1 --subnet-id subnet-0258dc9d1b6473d84 --tag-specifications ResourceType=instance,Tags=[{Key=usage,Value=roachtest},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-19780251-1748237910-81-n4cpu32},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=arm64},{Key=created,Value=2025-05-26T07:05:59Z},{Key=Name,Value=teamcity-19780251-1748237910-81-n4cpu32-0001},{Key=Cluster,Value=teamcity-19780251-1748237910-81-n4cpu32}] ResourceType=volume,Tags=[{Key=usage,Value=roachtest},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-19780251-1748237910-81-n4cpu32},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=arm64},{Key=created,Value=2025-05-26T07:05:59Z},{Key=Name,Value=teamcity-19780251-1748237910-81-n4cpu32-0001},{Key=Cluster,Value=teamcity-19780251-1748237910-81-n4cpu32}] --user-data file:///tmp/aws-startup-script1973893632 --iam-instance-profile Name=roachprod-testing --block-device-mapping file:///tmp/aws-block-device-mapping2586748814 --instance-market-options MarketType=spot,SpotOptions={SpotInstanceType=one-time,InstanceInterruptionBehavior=terminate} --output json: stderr:
An error occurred (MaxSpotInstanceCountExceeded) when calling the RunInstances operation: Max spot instance count exceeded: exit status 254 [owner=test-eng]
```

Parameters:
- cloud=aws
- coverageBuild=false
- cpu=32
- runtimeAssertionsBuild=false
- ssd=0
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)

Start with the roachtest README and the failure at test_runner.go:864, then trace the cluster_creation path that invokes AWS EC2 run-instances. Reproduce or inspect the reported TeamCity artifacts and the MaxSpotInstanceCountExceeded error. Done means identifying and addressing the roachtest failure mode, with a test or verified run showing cluster creation succeeds.

Written by the indexing model from the issue text.