fix build with swig 4.1.0
https://github.com/llvm/llvm-project/commit/f0a25fe0b746f56295d5c02116ba28d2f965c175

Index: lldb/bindings/python/python-typemaps.swig
--- lldb/bindings/python/python-typemaps.swig.orig
+++ lldb/bindings/python/python-typemaps.swig
@@ -439,7 +439,7 @@ bool SetNumberFromPyObject<double>(double &number, PyO
 
 %typemap(out) lldb::FileSP {
   $result = nullptr;
-  lldb::FileSP &sp = $1;
+  const lldb::FileSP &sp = $1;
   if (sp) {
     PythonFile pyfile = unwrapOrSetPythonException(PythonFile::FromFile(*sp));
     if (!pyfile.IsValid())
