CI: Rename to .condarc
- [ ] closes #56497 (Replace xxxx with the GitHub issue number)
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

With setup-micromamba 1.7.3, this is not an issue anymore.
I mistakenly assumed that only `.condarc` is a valid condarc file name. But in reality, all files ending with `.yml` are too (among others)

https://github.com/mamba-org/mamba/blob/c54c4b530e6638c8712f6246200d0f5a32410b46/libmamba/src/api/configuration.cpp#L955

Sorry about the inconvenience 😓  Ah no worries! Despite this, I think it's OK for us to rename this anyways