BUG: extra row created when calling to_excel for multi-index columns
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When multi-level columns are written into excel, use to_ Excel method, there will be an extra row in the saved xlsx file

![image](https://user-images.githubusercontent.com/20391209/165278268-c8319b4f-572b-4b37-8ba8-f0ed4318f053.png)

I tried to fix and welcome to comment for this update.



what happens when the index has a name, i.e. it creates an `index_label` in the code. I suspect this will fail and it will break tests? Thanks for the PR. It looks like this broke existing tests - can you add a test for the functionality you are proposing and make sure the existing ones are still working?  > 

OK. I will do that. Then pull request again here. This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. Thanks for the pull request, but it appears to have gone stale. If interested in continuing, please merge in the main branch, address any review comments and/or failing tests, and we can reopen.