tests: stabilize test-rename-merge2.t on Windows I have no idea why, but this shifted in b4057d001760. Differential Revision: https://phab.mercurial-scm.org/D8146

#require black

  $ cd $RUNTESTDIR/..
  $ black --config=black.toml --check --diff `hg files 'set:(**.py + grep("^#!.*python")) - mercurial/thirdparty/**'`