Create ${swig_target}-scripts target instead of lldb-python-scripts

This addresses the issue raised here https://reviews.llvm.org/rG02bf5632a94da6c3570df002804f8d3f79c11bfc
The `finish_swig_python` function might be called more than once so we need to create the distribution
component target based on the swig target.

Differential Revision: https://reviews.llvm.org/D86402