[CI Failure] SqlServerContainerFixture InitializeAsync fails with Docker port 1433 already in use on shared CI runner

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/33086828076
Build error leg or test failing: Tests / Run VS Code extension unit tests (Windows) / `Aspire.Hosting.Azure.Tests.AzureSqlPrincipalReconciliationTests`
Pull request: #19730

## Error Message

```
Docker.DotNet.DockerApiException : Docker API responded with status code=InternalServerError, response={"message":"failed to set up container networking: driver failed programming external connectivity on endpoint frosty_lehmann ...: failed to bind host port for 0.0.0.0::172.17.0.3:1433/tcp: address already in use"} at Aspire.Hosting.Azure.Tests.SqlServerContainerFixture.InitializeAsync()
```

## Description

SqlServerContainerFixture InitializeAsync fails with Docker port 1433 already in use on shared CI runner

**Type**: infra-failure

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-08-27 | [33086828076](https://github.com/microsoft/aspire/actions/runs/33086828076) | Tests / Run VS Code extension unit tests (Windows) | #19730 |

Start with Aspire.Hosting.Azure.Tests.SqlServerContainerFixture.InitializeAsync and the failing Aspire.Hosting.Azure.Tests.AzureSqlPrincipalReconciliationTests run from build 33086828076. Inspect how the fixture binds Docker port 1433 on the shared Windows runner. Done means the test no longer fails when that host port is already occupied.

Written by the indexing model from the issue text.