fix: remove unnecessary file inclusions from MANIFEST.in

Author: yoyolicoris

MANIFEST.in

@@ -1,6 +1 @@
-recursive-include torchlpc *.py
-recursive-include torchlpc *.h
-recursive-include torchlpc *.cpp
-recursive-include torchlpc *.c
-recursive-include torchlpc *.cu
 recursive-include torchlpc *.txt