Apply API changes for RequestCircuitPauseAsync

[ilonatommy]

Suggestions: #66798 (comment)

• Change ValueTask to a Task
• Add AbortSignal to stop the "pause deferring" work when connection is being teared down.
• The callback doesn't have bolean return value so it's expected not to be honored in the JS code.
  

  aspnetcore/src/Components/Web.JS/src/Platform/Circuits/CircuitStartOptions.ts

  Line 23 in b8f35c2

  onPauseRequested?: () => Promise<void>;

  
  This remark was based on stale method snippet, from before Implement Circuit.RequestCircuitPauseAsync #66265 (comment) design discussion.

Fixes #65062

[Copilot]

Pull request overview

This PR updates the server-side Blazor circuit pause API shape and aligns the JS client hook to support cancellation when the circuit is torn down, based on the API feedback in the linked issue.

Changes:

• Changed Circuit.RequestCircuitPauseAsync (and internal CircuitHost.RequestPauseAsync) from ValueTask<bool> to Task<bool> and updated call sites/tests accordingly.
• Updated the JS CircuitStartOptions.onPauseRequested callback signature to accept an AbortSignal and allow synchronous (void) or async (Promise<void>) completion.
• Added client-side aborting of the pause-deferral work during CircuitManager.dispose().

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/Components/Web.JS/src/Platform/Circuits/CircuitStartOptions.ts	Updates onPauseRequested typing to accept AbortSignal and allow sync/async completion.
src/Components/Web.JS/src/Platform/Circuits/CircuitManager.ts	Creates/aborts an AbortController for pause deferral and passes the signal into onPauseRequested.
src/Components/Server/test/Circuits/CircuitHostTest.cs	Updates tests to match the new Task<bool> return type.
src/Components/Server/src/PublicAPI.Unshipped.txt	Updates the declared public API signature to Task<bool>.
src/Components/Server/src/Circuits/CircuitHost.cs	Changes internal pause request method to Task<bool> and returns the dispatcher task directly.
src/Components/Server/src/Circuits/Circuit.cs	Updates public API to return Task<bool> and delegates to CircuitHost.