updates for pandas v2.2 and xarray v2024.02

[mathause]

• Closes fix datetime related warnings from pandas and xarray #397
• Fully documented, including CHANGELOG.rst

Updates for pandas v2.2 and xarray v2024.02:

• pandas made some changes to the date parsing in read_csv
• pandas and xarray made changes to the frequency strings (e.g. "A" -> "YE")
• also we set the minimum xarray version at v2023.04

For this PR it is now very helpful that we merged #398. (There may, however, be some intermediate xr & pd combinations that still create warnings)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.97%. Comparing base (9b0b76b) to head (0058495).
Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #404      +/-   ##
==========================================
+ Coverage   87.90%   87.97%   +0.07%     
==========================================
  Files          40       40              
  Lines        1745     1747       +2     
==========================================
+ Hits         1534     1537       +3     
+ Misses        211      210       -1     

Flag	Coverage Δ
unittests	87.97% <100.00%> (+0.07%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[veni-vidi-vici-dormivi]

Oh yes I see. But are the changes in pandas already in v2.0 (which we require) or only in v2.2 (which would need us to cover both versions)?

[mathause]

For the frequency strings I do version checks; the read_csv changes are available in both versions. And because we now have the min-all-deps it is tested with both pandas v2.0 and v2.2 and we can be reasonably confident it works in both versions.

[mathause]

thanks