Enabled the REDISTRIBUTION option in the Makefile for sky130A.
Corrected the convert_spectre.py to ignore .scs files, which have
no SPICE equivalent.
diff --git a/sky130/magic/sky130.tech b/sky130/magic/sky130.tech
index d000ffd..90e4240 100644
--- a/sky130/magic/sky130.tech
+++ b/sky130/magic/sky130.tech
@@ -3870,6 +3870,9 @@
  defaultsideoverlap allm4 metal4 allm5 metal5 47
 #endif (METAL5)
 
+#ifdef REDISTRIBUTION
+#endif (REDISTRIBUTION)
+
 # Devices:  Use document (...)
 
 variants (sim)