Sorry for not adding a test case for this. I'll set it up once I get home and can work on my PC—my current laptop is too slow to handle the full testing environment.

Also, I noticed the unit tests failed. Again, I will fix them once I get home.

Thanks for working on this fix for #60647!

This change successfully removes the code path containing the specific line (holidays = holidays + calendar.holidays().tolist()) identified in the issue and the comments.

However, there are a few points that probably deserve some attention:

Removed Functionality: This fix works by removing the if-else block. Was the functionality within that block (handling a non-numpy calendar object passed with holidays) intended or ever valid? Removing it is a potentially breaking change that should ideally be documented.

Exception Type: Raising ApplyTypeError here is a bit unusual, as it's typically for arithmetic operations returning NotImplemented. Would a ValueError or TypeError be more appropriate to signal invalid arguments during the setup phase?

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.