Tracking: Drop support for python 3.8

[dangotbanned]

Had quite the ordeal trying to avoid the bugs of Protocol in (#2064 (comment)).
If that compatibility code gets merged, I'd really like to remove it ASAP.
It adds a lot of complexity for a version almost 5 months past EOL

Note

Collected more info on Protocol issues in (#2294 (comment))

I collected a lot of info a while back in a similar issue for altair

• Preparing for Python 3.8 EOL vega/altair#3497

Downstream "<=3.8"

All projects listed in README.md#used-by have dropped 3.8 support, except:

• plotly
  • drop support for Python 3.8 plotly/plotly.py#5054
• scikit-lego
  • Consider dropping python 3.8 tests koaning/scikit-lego#734

Upstream

• Drop support for Python 3.8 python/typing_extensions#568
  • Dev dependency only

[FBruzzesi]

As mentioned in Discord, timebasedcv will keep working with the latest Narwhals version that supports python 3.8 (for python 3.8), thus let's not consider that a blocker for dropping support for 3.8.
The library is quite feature complete for now and I am not planning many developments that depends on new narwhals features

[dangotbanned]

#2084 (comment)

Got it, thanks @FBruzzesi - just edited the description

[dangotbanned]

Might be useful to decide on something like this moving forward

• Python version support policy python/typing_extensions#571

[dangotbanned]

Minimum version bumps

Dropping support for 3.8 will trigger these bumps

Package	Minimum	Source
pandas	1.1.3	https://pandas.pydata.org/docs/whatsnew/v1.1.3.html#added-support-for-new-python-version
modin	0.8.2	modin-project/modin#2371

narwhals/narwhals/utils.py

Lines 593 to 604 in faebf35

	MIN_VERSIONS: dict[Implementation, tuple[int, ...]] = {
	Implementation.PANDAS: (0, 25, 3),
	Implementation.MODIN: (0, 25, 3),
	Implementation.CUDF: (24, 10),
	Implementation.PYARROW: (11,),
	Implementation.PYSPARK: (3, 5),
	Implementation.POLARS: (0, 20, 3),
	Implementation.DASK: (2024, 8),
	Implementation.DUCKDB: (1,),
	Implementation.IBIS: (6,),
	Implementation.SQLFRAME: (3, 22, 0),
	}