fix #54564
- [x] closes #54564
- [x] Tests added and passed
- [x] All code checks passed
- [x] Added type annotations to new arguments/methods/functions: *No new functions.*
- [x] Added an entry in the latest `doc/source/whatsnew/v2.1.0.rst` file: *-> may this fix make it into a potential v2.0.4 instead?*

Note that I had to add a new `test6.xls` file to support the test, as pandas doesn't write `.xls` files, and I didn't want to add `xlwt` to the dev requirements just to generate the file on the fly. However, all `test1` to `test5` test-files exist in various excel file variants. Should `test6` be available in other versions too? How have those previous test files been generated? Looks like the added test needs to handle Window's 32 bit default Yea, just noticed that. @burnpanck - NumPy has a bit of an oddity where ints default to 32 bit on Windows (they're fixing this in 2.0 I believe). Can you specify `dtype="int64"` when you create `expected` in your test.

https://github.com/pandas-dev/pandas/actions/runs/5902921221/job/16011817499?pr=54567#step:5:1041

Edit: I forgot this has a mix of columns. You can use astype on the integer one. Thanks @burnpanck 