roachtest: cdc/message-too-large-error failed

roachtest.cdc/message-too-large-error [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21476912?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21476912?buildTab=artifacts#/cdc/message-too-large-error) on release-25.4.15-rc @ [4913a926920d3003e1223156615a6a6a7d524b59](https://github.com/cockroachdb/cockroach/commits/4913a926920d3003e1223156615a6a6a7d524b59):

```
(test_runner.go:1493).runTest: test timed out (15m0s)
test artifacts and logs in: /artifacts/cdc/message-too-large-error/cpu_arch=arm64/run_1
```

Parameters:
- arch=arm64
- cloud=aws
- coverageBuild=false
- cpu=4
- encrypted=false
- fs=ext4
- localSSD=true
- metamorphicLeases=epoch
- 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)

_Grafana is not yet available for aws clusters_

/cc @cockroachlabs/cdc

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*cdc/message-too-large-error.*&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 test_runner.go:1493, then inspect the linked TeamCity logs and artifacts under /artifacts/cdc/message-too-large-error/cpu_arch=arm64/run_1. Reproduce the 15-minute timeout for cdc/message-too-large-error and trace the CDC test until the cause is identified; done means the test completes successfully under the reported configuration.

Written by the indexing model from the issue text.