Remove invalid asserts from WslMirroredNetworking.cpp

[OneBlue]

Summary of the Pull Request

This change removes two invalid asserts from src/windows/service/exe/WslMirroredNetworking.cpp

PR Checklist

• Closes: Link to issue #xxx
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated if needed and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated if needed
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[Copilot]

Pull request overview

This PR removes two invalid assertions from WslMirroredNetworking.cpp that were checking for State::Started in callback functions. These assertions were invalid because callbacks can fire during shutdown after the state has been set to State::Stopped but before the callbacks are unregistered, creating a race condition. The code already handles this correctly by checking for State::Stopped immediately after the assertions and returning early.

Changes:

• Removed invalid WI_ASSERT(manager->m_state == State::Started) from HcnServiceConnectionTimerCallback
• Removed invalid WI_ASSERT(manager->m_state == State::Started) from HcnCallback