bisect: bypass changectx when translating revs to nodes

When resolving the revset given by the user into node hashes, use the changelog
to perform the translation rather than the repo object. This avoids the overhead
of constructing a changectx which is immediately discarded.

mercurial/commands.py

@@ -1035,7 +1035,7 b' def bisect('
     state = hbisect.load_state(repo)
 
     if rev:
-        nodes = [repo[i].node() for i in logcmdutil.revrange(repo, rev)]
+        nodes = [repo.changelog.node(i) for i in logcmdutil.revrange(repo, rev)]
     else:
         nodes = [repo.lookup(b'.')]