Remove squeeze argument from groupby (#16312)

In pandas, this argument was deprecated in pandas 1.x and removed in pandas 2.x. xref pandas-dev/pandas#33218

Looks like in cudf this argument was never implemented, so to align with pandas, I think it should be OK to just remove this argument

Authors:
  - Matthew Roeschke (https://github.com/mroeschke)

Approvers:
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: #16312

Author: mroeschke

python/cudf/cudf/core/dataframe.py

@@ -4306,7 +4306,6 @@ def groupby(
         as_index=True,
         sort=no_default,
         group_keys=False,
-        squeeze=False,
         observed=True,
         dropna=True,
     ):
@@ -4317,7 +4316,6 @@ def groupby(
             as_index,
             sort,
             group_keys,
-            squeeze,
             observed,
             dropna,
         )

python/cudf/cudf/core/indexed_frame.py

@@ -5249,7 +5249,6 @@ def groupby(
         as_index=True,
         sort=no_default,
         group_keys=False,
-        squeeze=False,
         observed=True,
         dropna=True,
     ):
@@ -5259,11 +5258,6 @@ def groupby(
         if axis not in (0, "index"):
             raise NotImplementedError("axis parameter is not yet implemented")
 
-        if squeeze is not False:
-            raise NotImplementedError(
-                "squeeze parameter is not yet implemented"
-            )
-
         if not observed:
             raise NotImplementedError(
                 "observed parameter is not yet implemented"

python/cudf/cudf/core/series.py

@@ -3368,7 +3368,6 @@ def groupby(
         as_index=True,
         sort=no_default,
         group_keys=False,
-        squeeze=False,
         observed=True,
         dropna=True,
     ):
@@ -3379,7 +3378,6 @@ def groupby(
             as_index,
             sort,
             group_keys,
-            squeeze,
             observed,
             dropna,
         )