Increase BrowserTokenAuthenticationTests timeouts

[adamint]

Description

Similarly to the 'fixes' to previous playwright tests, I think we just need to increase the timeout for these tests. Increased in all tests in the class for consistency.

relevant: #9345 and #9697

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Link to aspire-docs issue (consider using one of the following templates):
      • New (or update) doc-idea template
      • New breaking-change template
      • New diagnostic template
  • No

[Copilot]

Pull Request Overview

This PR increases the default timeout for all Playwright interactions in BrowserTokenAuthenticationTests to TestConstants.LongTimeoutTimeSpan, replacing previous default timeouts and a magic constant, and removes the [QuarantinedTest] attributes now that the tests should be stable.

• Updated .DefaultTimeout() calls on GotoAsync, FillAsync, ClickAsync, ToBeVisibleAsync, and GetAttributeAsync to use TestConstants.LongTimeoutTimeSpan
• Removed the pageVisibleTimeout local constant in favor of the shared timeout
• Removed [QuarantinedTest] annotations now that tests rely on extended timeouts

Comments suppressed due to low confidence (2)

tests/Aspire.Dashboard.Tests/Integration/Playwright/BrowserTokenAuthenticationTests.cs:32

• The [QuarantinedTest] attribute was removed. If these tests are still known to be flaky on CI, consider retaining or migrating this metadata to avoid false negatives in automated runs.

    [Fact]

tests/Aspire.Dashboard.Tests/Integration/Playwright/BrowserTokenAuthenticationTests.cs:58

• The [QuarantinedTest] attribute was removed. Ensure these tests are reliable with the new timeouts or reapply quarantine metadata for any still-flaky scenarios.

    [Fact]

[radical]

Could you please change Fixes https://github.com/dotnet/aspire/issues/9345 and fixes https://github.com/dotnet/aspire/issues/9697 to Attempts to fixing https://github.com/dotnet/aspire/issues/9345 and https://github.com/dotnet/aspire/issues/9697, so it does not close the issue for the quarantined test? We can close once it has ~100 successful runs on the Outerloop workflow.