fix ~ not work as startingDirectory for WSL (#12050)

<!-- Enter a brief description/summary of your PR here. What does it fix/what does it change/how was it tested (even manually, if necessary)? -->
## Summary of the Pull Request
fix #11432
<!-- Other than the issue solved, is this relevant to any other issues/existing PRs? --> 
## References

<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist
* [x] Closes #11432
* [x] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA
* [ ] Tests added/passed
* [ ] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

<!-- Provide a more detailed description of the PR, other things fixed or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

<!-- Describe how you validated the behavior. Add automated tests wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed
compiled and verified that "\~"  ,  "/usr/bin"  ,  "~/.config" and "/" as stating directory didn't get relative path resolve
verified that '.' did

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -941,8 +941,8 @@ namespace winrt::TerminalApp::implementation
             // process until later, on another thread, after we've already
             // restored the CWD to it's original value.
             winrt::hstring newWorkingDirectory{ settings.StartingDirectory() };
-            if (newWorkingDirectory.size() <= 1 ||
-                !(newWorkingDirectory[0] == L'~' || newWorkingDirectory[0] == L'/'))
+            if (newWorkingDirectory.size() == 0 || newWorkingDirectory.size() == 1 &&
+                                                       !(newWorkingDirectory[0] == L'~' || newWorkingDirectory[0] == L'/'))
             { // We only want to resolve the new WD against the CWD if it doesn't look like a Linux path (see GH#592)
                 std::wstring cwdString{ wil::GetCurrentDirectoryW<std::wstring>() };
                 std::filesystem::path cwd{ cwdString };