Fix TermControl initialization to pre-seed working dir (#9397)

## PR Checklist
* [x] Closes #8969
* [x] CLA signed.
* [ ] Tests added/passed
* [ ] Documentation updated.
* [ ] Schema updated.
* [ ] I've discussed this with core contributors already.

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## Detailed Description of the Pull Request / Additional comments

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(cherry picked from commit 19bd0c9)

src/cascadia/TerminalControl/TermControl.cpp

@@ -87,6 +87,9 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
 
         _terminal = std::make_unique<::Microsoft::Terminal::Core::Terminal>();
 
+        // GH#8969: pre-seed working directory to prevent potential races
+        _terminal->SetWorkingDirectory(_settings.StartingDirectory());
+
         auto pfnWarningBell = std::bind(&TermControl::_TerminalWarningBell, this);
         _terminal->SetWarningBellCallback(pfnWarningBell);