commands: drop support for legacy ^cmd registration (API)

mercurial/commands.py

@@ -6248,16 +6248,6 b' def version_(ui, **opts):'
 def loadcmdtable(ui, name, cmdtable):
     """Load command functions from specified cmdtable
     """
-    cmdtable = cmdtable.copy()
-    for cmd in list(cmdtable):
-        if not cmd.startswith('^'):
-            continue
-        ui.deprecwarn("old-style command registration '%s' in extension '%s'"
-                      % (cmd, name), '4.8')
-        entry = cmdtable.pop(cmd)
-        entry[0].helpbasic = True
-        cmdtable[cmd[1:]] = entry
-
     overrides = [cmd for cmd in cmdtable if cmd in table]
     if overrides:
         ui.warn(_("extension '%s' overrides commands: %s\n")