Flaky test: Microsoft.Extensions.Time.Testing.Test.TimerTests.CreateTimer_WhenDisposed_RemovesWaiterFromQueue

### Description

This test appears to be flaky:
`Microsoft.Extensions.Time.Testing.Test.TimerTests.CreateTimer_WhenDisposed_RemovesWaiterFromQueue`

The test logic mentions timers so it's likely a timing thing.

Example build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1083349&view=ms.vss-test-web.build-test-results-tab&runId=29475172&resultId=111586&paneView=debug

Test failure output:
```
Assert.Equal() Failure: Values differ
Expected: 1
Actual: 0
```

Stack trace:
```
at Microsoft.Extensions.Time.Testing.Test.TimerTests.CreateTimer_WhenDisposed_RemovesWaiterFromQueue() in D:\a\_work\1\s\test\Libraries\Microsoft.Extensions.TimeProvider.Testing.Tests\TimerTests.cs:line 208
```

### Reproduction Steps

Retry the test in CI several times.

### Expected behavior

The test should be deterministic.

### Actual behavior

It is flaky.

### Regression?

_No response_

### Known Workarounds

_No response_

### Configuration

_No response_

### Other information

_No response_