branchmap: use the proper experimental name in cacheutil

Otherwise they are not properly copied around.

mercurial/cacheutil.py

@@ -1,25 +1,25
 # scmutil.py - Mercurial core utility functions
 #
 #  Copyright Olivia Mackall <[e-mail]> and other
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import annotations
 
 from . import repoview
 
 
 def cachetocopy(srcrepo):
     """return the list of cache file valuable to copy during a clone"""
     # In local clones we're copying all nodes, not just served
     # ones. Therefore copy all branch caches over.
     cachefiles = [b'branch2']
     cachefiles += [b'branch2-%s' % f for f in repoview.filtertable]
-    cachefiles += [b'branch3']
-    cachefiles += [b'branch3-%s' % f for f in repoview.filtertable]
+    cachefiles += [b'branch3-exp']
+    cachefiles += [b'branch3-exp-%s' % f for f in repoview.filtertable]
     cachefiles += [b'rbc-names-v2', b'rbc-revs-v2']
     cachefiles += [b'tags2']
     cachefiles += [b'tags2-%s' % f for f in repoview.filtertable]
     cachefiles += [b'hgtagsfnodes1']
     return cachefiles