upb: merge ":collections" into ":message"

PiperOrigin-RevId: 569594353
diff --git a/python/map.c b/python/map.c
index bd9022d..a1d75de 100644
--- a/python/map.c
+++ b/python/map.c
@@ -33,7 +33,7 @@
 #include "python/convert.h"
 #include "python/message.h"
 #include "python/protobuf.h"
-#include "upb/collections/map.h"
+#include "upb/message/map.h"
 #include "upb/reflection/def.h"
 
 // -----------------------------------------------------------------------------