Fix wxWebViewEdge build with standard-conforming compilers

Convert wxCoTaskMemPtr<wchar_t> to wxString explicitly as doing it
implicitly required 2 user-defined conversions which is not allowed in
standard C++ (but works with MSVC).

Also get rid of a not really necessary temporary wxString variable and
just perform this case when constructing wxStringTokenizer.

Closes #22170.

src/msw/webview_edge.cpp

@@ -989,8 +989,7 @@ wxVersionInfo wxWebViewFactoryEdge::GetVersionInfo()
             wxWebViewEdgeImpl::ms_browserExecutableDir.wc_str(), &nativeVersionStr);
         if (SUCCEEDED(hr) && nativeVersionStr)
         {
-            wxString versionStr = nativeVersionStr;
-            wxStringTokenizer tk(versionStr, ". ");
+            wxStringTokenizer tk(wxString(nativeVersionStr), ". ");
             // Ignore the return value because if the version component is missing
             // or invalid (i.e. non-numeric), the only thing we can do is to ignore
             // it anyhow.