PERF: Fix groupby skipna performance

[snitish]

• closes PERF: Regression in groupby ops from adding skipna #60870
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations 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.

[snitish]

| Change | Before [3979e954] <main> | After [22245da4] <issue60870> | Ratio | Benchmark (Parameter) | |----------|----------------------------|---------------------------------|---------|----------------------------------------------------------------------| | | 30.1±1ms | 30.2±0.8ms | 1.00 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'all') | | | 31.6±1ms | 31.7±0.3ms | 1.00 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'any') | | | 21.2±0.5ms | 22.0±0.3ms | 1.04 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'first') | | | 24.1±0.3ms | 22.3±0.5ms | 0.92 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'idxmax') | | | 22.1±0.2ms | 21.7±0.3ms | 0.98 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'idxmin') | | | 20.5±0.4ms | 21.7±0.3ms | 1.06 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'last') | | | 24.2±0.6ms | 22.5±3ms | 0.93 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'max') | | - | 29.9±0.4ms | 26.8±0.3ms | 0.90 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'mean') | | | 138±1ms | 139±3ms | 1.01 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'median') | | | 23.9±0.5ms | 20.9±1ms | ~0.87 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'min') | | | 21.5±0.6ms | 18.9±1ms | ~0.88 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'prod') | | | 31.8±3ms | 25.8±1ms | ~0.81 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'sum') | | - | 33.0±0.8ms | 28.5±0.3ms | 0.86 | groupby.GroupByCythonAgg.time_frame_agg('float64', 'var') | | | 35.3±0.3ms | 34.7±0.2ms | 0.98 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'all') | | | 38.1±0.4ms | 38.0±0.4ms | 1.00 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'any') | | | 33.7±0.3ms | 34.8±0.8ms | 1.03 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'first') | | | 36.3±0.3ms | 36.3±0.3ms | 1.00 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'last') | | - | 35.4±0.3ms | 31.8±0.3ms | 0.90 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'max') | | - | 46.0±1ms | 41.4±0.4ms | 0.90 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'mean') | | | 200±6ms | 197±3ms | 0.98 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'median') | | - | 35.0±0.9ms | 31.3±0.8ms | 0.90 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'min') | | | 34.2±0.6ms | 35.8±0.9ms | 1.05 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'prod') | | | 45.6±0.5ms | 44.1±0.5ms | 0.97 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'sum') | | | 51.4±0.5ms | 46.2±1ms | ~0.90 | groupby.GroupByCythonAggEaDtypes.time_frame_agg('Float64', 'var') | 

cc: @rhshadrach

[rhshadrach]

lgtm, merging main should get the CI green.

[mroeschke]

Thanks @snitish