release: Finish preparation for 4.17.4

.release.cfg

@@ -1,14 +1,16 b''
 [DEFAULT]
 done = false
 
 [task:bump_version]
 done = true
 
 [task:fixes_on_stable]
+done = true
 
 [task:pip2nix_generated]
+done = true
 
 [release]
-state = in_progress
+state = prepared
 version = 4.17.4