Pylint fixes, remove deprecated functions

[Zeitsperre]

Pull Request Checklist:

• This PR addresses an already opened issue (for bug fixes / features)
  • This PR fixes #xyz
• Tests for the changes have been added (for bug fixes / features)
  • (If applicable) Documentation has been added / updated (for bug fixes / features)
• CHANGELOG.rst has been updated (with summary of main changes)
  • Link to issue (:issue:number) and pull request (:pull:number) has been added

What kind of change does this PR introduce?

• Adjust code base to address several pylint-related warnings.
• Removes several deprecated calendar functions.
• Pins the vulture dependency in environment.yml
• Employed casting to deal with a few numpy * xarray typing issues.
• Addressed a couple warnings related to pint usage.

Does this PR introduce a breaking change?

Yes, several calendar-related functions that were deprecated and slated for removal in xclim v0.50 and v0.51 have been removed. These will need to be listed in the CHANGELOG.rst.

Other Information:

I'm now a conda-forge maintainer for vulture, haha (https://github.com/conda-forge/vulture-feedstock)

[coxipi]

looks good to me, but maybe double check the loops that you changed

[Zeitsperre]

@aulemahal @coxipi This is good for final review!

[coxipi]

approved

[Zeitsperre]

The notebooks have been fixed in #1889. It likely makes more sense to merge that PR first before this one.

[coveralls]

coverage: 89.393% (+0.2%) from 89.155%
when pulling faec7d4 on pylint-fixes
into de8b8b8 on main.

[Zeitsperre]

@aulemahal

I've made one or two small breaking changes:

• I've migrated xclim.core to use absolute imports instead of explicit relative imports (from xclim.core import ...)
• I've factored out a few small objects into hidden _types.py and _exceptions.py under xclim.core. The goal here being to reduce the number of time xclim.core.utils is imported throughout the module via its many members. Technically, this is breaking (and there are possibly other objects that might make sense being moved).

The rest of the changes are to clarify internal logic within functions via renaming. Thanks in advance for the re-review

[aulemahal]

Ah! Well done, thanks.