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/F/nodes=3/cpu=32/uniform) on release-25.2 @ [cfe971ca2dbac85aed9e65577feab2c87af2bc1d](https://github.com/cockroachdb/cockroach/commits/cfe971ca2dbac85aed9e65577feab2c87af2bc1d):

```
test ycsb/F/nodes=3/cpu=32/uniform 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=created,Value=2025-05-26T07:18:18Z},{Key=Name,Value=teamcity-19780251-1748237910-94-n4cpu32-0003},{Key=Cluster,Value=teamcity-19780251-1748237910-94-n4cpu32},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-19780251-1748237910-94-n4cpu32},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=arm64}] ResourceType=volume,Tags=[{Key=usage,Value=roachtest},{Key=created,Value=2025-05-26T07:18:18Z},{Key=Name,Value=teamcity-19780251-1748237910-94-n4cpu32-0003},{Key=Cluster,Value=teamcity-19780251-1748237910-94-n4cpu32},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-19780251-1748237910-94-n4cpu32},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=arm64}] --user-data file:///tmp/aws-startup-script3073211009 --iam-instance-profile Name=roachprod-testing --block-device-mapping file:///tmp/aws-block-device-mapping113316192 --instance-market-options MarketType=spot,SpotOptions={SpotInstanceType=one-time,InstanceInterruptionBehavior=terminate} --output json: stderr:
An error occurred (InsufficientInstanceCapacity) when calling the RunInstances operation (reached max retries: 2): We currently do not have sufficient c7gd.8xlarge capacity in the Availability Zone you requested (us-east-2a). Our system will be working on provisioning additional capacity. You can currently get c7gd.8xlarge capacity by not specifying an Availability Zone in your request or choosing us-east-2b, us-east-2c.: 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)

Same failure on other branches

- #147280 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.1-rc]
- #147279 roachtest: cluster_creation failed [O-roachtest O-robot O-rsg T-testeng X-infra-flake branch-master]
- #147278 roachtest: cluster_creation failed [O-roachtest O-robot O-rsg T-testeng X-infra-flake branch-master]
- #147277 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.1-rc]
- #147274 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.0-rc]
- #147205 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #147204 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #147203 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #147202 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #147201 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]

/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-50971

Start with pkg/cmd/roachtest/README.md and the linked TeamCity log and artifacts for the ycsb/F cluster_creation failure; compare the repeated reports across branches. Before coding, confirm the intended change and success condition for the AWS InsufficientInstanceCapacity error, since this issue records a failure but does not specify a fix.

Written by the indexing model from the issue text.