add a replacement API for PyCObject, PyCapsule #5630

All stdlib modules with C-APIs now use this.

Patch by Larry Hastings
diff --git a/Include/pyexpat.h b/Include/pyexpat.h
index 1e79f4e..5340ef5 100644
--- a/Include/pyexpat.h
+++ b/Include/pyexpat.h
@@ -4,6 +4,7 @@
 /* note: you must import expat.h before importing this module! */
 
 #define PyExpat_CAPI_MAGIC  "pyexpat.expat_CAPI 1.0"
+#define PyExpat_CAPSULE_NAME "pyexpat.expat_CAPI"
 
 struct PyExpat_CAPI 
 {