Add test for #32108 (error with groupby on series with period index) (#33105)
Add test for #32108 (error with groupby on series with period index) (#33105)


dsm054/pandas,gfyoung/pandas,pandas-dev/pandas,gfyoung/pandas,jorisvandenbossche/pandas,dsm054/pandas,gfyoung/pandas,pandas-dev/pandas,jorisvandenbossche/pandas,rs2/pandas,gfyoung/pandas,jreback/pandas,datapythonista/pandas,rs2/pandas,gfyoung/pandas,jreback/pandas,dsm054/pandas,datapythonista/pandas,pandas-dev/pandas,jorisvandenbossche/pandas,jreback/pandas,pandas-dev/pandas,dsm054/pandas,dsm054/pandas,jreback/pandas,rs2/pandas,rs2/pandas,jorisvandenbossche/pandas,datapythonista/pandas,datapythonista/pandas,jreback/pandas