fix: don't use forward-declared Ptr types in meta/

This would cause ODR violations when those headers were included in
other places that also included stuff like "Version.h" (note the
"meta/Version.h"), which can cause problems, especially in LTO.

Signed-off-by: flow <flowlnlnln@gmail.com>

launcher/ui/dialogs/VersionSelectDialog.cpp

@@ -120,7 +120,7 @@ void VersionSelectDialog::selectRecommended()
     m_versionWidget->selectRecommended();
 }
 
-BaseVersionPtr VersionSelectDialog::selectedVersion() const
+BaseVersion::Ptr VersionSelectDialog::selectedVersion() const
 {
     return m_versionWidget->selectedVersion();
 }