BUG: Change default of group_keys to True (#51627)

Author: rhshadrach

pandas/core/frame.py

@@ -8211,7 +8211,7 @@ def groupby(
         level: IndexLabel | None = None,
         as_index: bool = True,
         sort: bool = True,
-        group_keys: bool | lib.NoDefault = no_default,
+        group_keys: bool = True,
         observed: bool = False,
         dropna: bool = True,
     ) -> DataFrameGroupBy:

pandas/core/series.py

@@ -1969,7 +1969,7 @@ def groupby(
         level: IndexLabel = None,
         as_index: bool = True,
         sort: bool = True,
-        group_keys: bool | lib.NoDefault = no_default,
+        group_keys: bool = True,
         observed: bool = False,
         dropna: bool = True,
     ) -> SeriesGroupBy: