Remove RestartTimer() from AvAudioNode Callback

[TheCodeTraveler]

Description of Change

After confirming that the AvAudioNode callback is triggered during silence, this PR removes RestartTimer() from the AvAudioNode callback on iOS + MacCatalyst when installing a tap on the bus.

Linked Issues

• Fixes [BUG] AutoStopSilenceTimeout for SpeechToTextOptions doesn't work on iOS #3195

PR Checklist

• Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• Has tests (if omitted, state reason in description)
• Has samples (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Changes adhere to coding standard
• Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pulls

Additional information

[Copilot]

Pull request overview

Fixes iOS + MacCatalyst (and macOS equivalents) silence auto-stop behavior for SpeechToText by ensuring the silence timer is not continuously reset by AVAudioEngine tap buffers that are delivered even during silence. This aligns AutoStopSilenceTimeout behavior with the intended “stop after silence” semantics (Fixes #3195).

Changes:

• Removed RestartTimer() from AVAudioNode.InstallTapOnBus callbacks so the silence timer isn’t reset on every incoming (silent) buffer.
• Simplified tap callbacks to only append buffers to the recognition request.
• Updated macOS GetBusOutputFormat usage to match the tapped bus.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/SpeechToTextImplementation.macos.cs	Stop resetting the silence timer from the AVAudioEngine tap; align bus format retrieval with the tap bus.
src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/SpeechToTextImplementation.ios.cs	Stop resetting the silence timer from the AVAudioEngine tap to allow AutoStopSilenceTimeout to elapse during silence.
src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/OfflineSpeechToTextImplementation.macos.cs	Same fix as online implementation for offline recognition on macOS.
src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/OfflineSpeechToTextImplementation.ios.cs	Same fix as online implementation for offline recognition on iOS/MacCatalyst.