Add support for Python=3.12

[valeriupredoi]

Once ESMValGroup/ESMValCore#2228 *allowing support for Python=3.12 in ESMValCore), we should see what roadblocks we have here, so am starting early. That Core PR is currently roadblocked only by prospector not being Python=3.12-compatible, but we're working on that.

Current issues

• esmpy/esmf >=8.6.0 conflicting in deps with ncl - see Unpin esmf and set it to free like upstream and bump build number conda-forge/ncl-feedstock#155 that doesn't work until NCL fix the issue with esmf upstream (I'd do it myself, but I got absolutely no clues how to, did open an issue tho Support for esmf >=8.6.0 NCAR/ncl#213) everyone via gdal/libgdal -> very brittle env that can only be solved only for old gdal 3.7.2 (that is, in turn, rejected by such likes as fiona); gotta wait until the ecosystem settles
• prospector issue
• psy-reg needs attention see Rebuild for python312 conda-forge/psy-reg-feedstock#18

Previous issues

• esmvalcore (prospector is the only roadblock there)
• ncl -> issue with builds against later proj's (>=9.3.1) support for proj >=9.3.1 NCAR/ncl#210
• r-akima needs unpinned unpin r-akima #3564
• psy- suite (also at install point they need to move from SafeConfigParser to regular parser, via AttributeError: module 'configparser' has no attribute 'SafeConfigParser' - SafeConfigParser has now been fully retired in 3.12) psy-stuff has now been updated to support 3.12 via @Chilipp good work, see Rebuild for python312 conda-forge/psyplot-feedstock#27 - except psy-reg which still needs a rebuild (with Philipp's new infrastructure)
• prospector (direct dep here, and as we have it via esmvalcore) - needs update some dependency pins so we can build with Python=3.12 landscapeio/prospector#645 that, in turn, needs a fix/workaround of master proposed in Mechanical fix/workaround for tests/tools/pyroma/test_pyroma_tool.py landscapeio/prospector#658
• all else is fine!

Also closes #3642

[valeriupredoi]

@ESMValGroup/technical-lead-development-team we are inching closer to suppoert Python=3.12 - have a look here https://github.com/ESMValGroup/ESMValTool/actions/runs/8453069262/job/23154935341?pr=3501 - only 4 dependencies need to be rebuilt fro 3.12 - I am a bit at a deadend with prospector though, been waiting on my PR to be merged there since last November; the psy- pkgs I believe that will be updated soon, will go pinch Philipp there; the 🐘 in the room is NCL - am gonna go see what's the atmosphere there; and the pesky one is r-akima - we need to unpin it! 🍺

[valeriupredoi]

OK the issue with NCL is not as bad as I thought - it's compatibility with later proj's see NCAR/ncl#210

[valeriupredoi]

note to self: rerun tests sooner than later, psy-maps only made it to conda-forge just about an hour ago

done 🥳

[valeriupredoi]

@bouweandela since you are the number one fan of my sort of work these days, here's some good news - we managed to have this show running fine with Py312 - two issues still remain: psy-reg needs to get to 1.5.0 (and py312-sompatible) and prospector, as always 🍺

[Chilipp]

psy-reg needs to get to 1.5.0 (and py312-sompatible)

one urgent issue remains on my todo-list @valeriupredoi, but chances are good that I can work on this within this week 🙈

[valeriupredoi]

@Chilipp that's wonderful news, many thanks, mate 🍺 Do let me know if I can help 👍

[bouweandela]

I checked with the Codacy folks about ruff support, but it's not a very high priority for them, unfortunately.

[valeriupredoi]

@bouweandela I got a rather positive reply from @mrfyda at Codacy, check it out codacy/codacy-engine-scala-seed#59 (comment)

[valeriupredoi]

in the meantime, I'd argue we remove prospector from our build deps - my view is that Python 3.12 support is probably more important than having prospector in the deps list 😁

[valeriupredoi]

@Chilipp is an absolute legend, and now we have the full Psy suite Python 3.12-able, psy-reg too https://anaconda.org/conda-forge/psy-reg - this, my dear Pythoneers, concludes the work on this PR! (nothing we can do about prospector BTW) 🍺