Fix use-after-free in WSLCContainerImpl exec-process teardown

[yao-msft]

Summary of the Pull Request

Change m_processes to use weak pointers instead of raw pointers. Use lock() to pin on use.

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

Existing tests

[Copilot]

Pull request overview

This PR addresses a use-after-free risk during container exec-process teardown by changing WSLCContainerImpl’s tracking of exec process controls from raw pointers to std::weak_ptr, and pinning controls with lock() before invoking teardown callbacks.

Changes:

• Replace m_processes storage from std::vector<DockerExecProcessControl*> to std::vector<std::weak_ptr<DockerExecProcessControl>>.
• Update exec creation to use std::make_shared<DockerExecProcessControl>() and store weak references in m_processes.
• Remove WSLCContainerImpl::OnProcessReleased() and update teardown paths (ReleaseProcesses(), container destructor) to snapshot the weak list and safely notify live controls via weak_ptr::lock().

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/windows/wslcsession/WSLCProcessControl.cpp	Removes destructor callback into the container, relying on weak tracking to avoid UAF during teardown.
src/windows/wslcsession/WSLCContainer.h	Updates m_processes to store std::weak_ptr<DockerExecProcessControl> instead of raw pointers.
src/windows/wslcsession/WSLCContainer.cpp	Switches exec control creation to shared_ptr, stores weak refs, and pins controls with lock() during teardown notifications.

[OneBlue]

LGTM ! It's wild that we never hit this during testing

[OneBlue]

nit: I'd recommend removing the avoids the use after free since once merged, that comment will refer to an issue that won't exist anymore

[OneBlue]

nit: This destructor can be removed since it's not doing anything