[CI Failure] Flaky: ParentProcessLifetimeScopesExecutableAndContainerToParentProcess fails due to DCP timestamp parsing BadRequest

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/29217376246
Build error leg or test failing: Tests / Hosting-1 / Hosting-1 (8-core-ubuntu-latest) / `Aspire.Hosting.Tests.DistributedApplicationTests.ParentProcessLifetimeScopesExecutableAndContainerToParentProcess`
Pull request: #18752

## Error Message

```
k8s.Autorest.HttpOperationException: Operation returned an invalid status code 'BadRequest', response body {"message":"Executable in version \"v1\" cannot be handled as a Executable: parsing time \"0001-01-01T00:02:47Z\" as \"2006-01-02T15:04:05.000000Z07:00\": cannot parse \"Z\" as \".000000\"","reason":"BadRequest","code":400}
at Aspire.Hosting.Dcp.KubernetesService in /_/src/Aspire.Hosting/Dcp/KubernetesService.cs:line 139
```

## Description

Flaky: ParentProcessLifetimeScopesExecutableAndContainerToParentProcess fails due to DCP timestamp parsing BadRequest

**Type**: flaky-test

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-07-13 | [29217376246](https://github.com/microsoft/aspire/actions/runs/29217376246) | Tests / Hosting-1 / Hosting-1 (8-core-ubuntu-latest) | #18752 |

Start with Aspire.Hosting.Tests.DistributedApplicationTests.ParentProcessLifetimeScopesExecutableAndContainerToParentProcess and inspect the failure at src/Aspire.Hosting/Dcp/KubernetesService.cs:139. Run the Hosting-1 test or the linked build to determine why the DCP timestamp is rejected; done means the test no longer produces this BadRequest and remains reliable.

Written by the indexing model from the issue text.