chore: add groupby benchmark q10, update q8 (#809)

* chore: add groupby benchmark q10, update q8

* update code

Author: Genesis929

scripts/benchmark/db-benchmark/groupby/G1_1e9_1e2_5_0/q10.py

@@ -0,0 +1,16 @@
+# Contains code from https://github.com/duckdblabs/db-benchmark/blob/master/pandas/groupby-pandas.py
+
+import bigframes.pandas as bpd
+
+print("Groupby benchmark 10: sum v3 count by id1:id6")
+
+x = bpd.read_gbq("bigframes-dev-perf.dbbenchmark.G1_1e9_1e2_5_0")
+
+ans = x.groupby(
+    ["id1", "id2", "id3", "id4", "id5", "id6"], as_index=False, dropna=False
+).agg({"v3": "sum", "v1": "size"})
+print(ans.shape)
+chk = [ans["v3"].sum(), ans["v1"].sum()]
+print(chk)
+
+bpd.reset_session()

scripts/benchmark/db-benchmark/groupby/G1_1e9_1e2_5_0/q8.py

@@ -12,6 +12,7 @@
     .groupby("id6", as_index=False, dropna=False)
     .head(2)
 )
+ans = ans.reset_index(drop=True)
 print(ans.shape)
 chk = [ans["v3"].sum()]
 print(chk)