Update HACKING.md

Co-authored-by: Martin Pitt <[email protected]>

HACKING.md

@@ -184,7 +184,7 @@ integration tests locally.
 
 ## Python bridge
 
-Cockpit currently has an experimental replacement for `cockpit-bridge`
+Most distro releases now ship a replacement for the C bridge
 written in Python.  It resides in `src/cockpit` with most of its rules in
 `src/Makefile.am`.  This directory was chosen because it matches the standard
 so-called "src layout" convention for Python packages, where each package