chore: cleanup type errors in tests/system/small/operations/test_datetimes.py (#769)

Author: Genesis929

bigframes/series.py

@@ -783,10 +783,10 @@ def pow(self, other: float | int | Series) -> Series:
     def rpow(self, other: float | int | Series) -> Series:
         return self._apply_binary_op(other, ops.pow_op, reverse=True)
 
-    def __lt__(self, other: float | int | Series) -> Series:  # type: ignore
+    def __lt__(self, other: float | int | str | Series) -> Series:
         return self.lt(other)
 
-    def __le__(self, other: float | int | Series) -> Series:  # type: ignore
+    def __le__(self, other: float | int | str | Series) -> Series:
         return self.le(other)
 
     def lt(self, other) -> Series:
@@ -795,10 +795,10 @@ def lt(self, other) -> Series:
     def le(self, other) -> Series:
         return self._apply_binary_op(other, ops.le_op)
 
-    def __gt__(self, other: float | int | Series) -> Series:  # type: ignore
+    def __gt__(self, other: float | int | str | Series) -> Series:
         return self.gt(other)
 
-    def __ge__(self, other: float | int | Series) -> Series:  # type: ignore
+    def __ge__(self, other: float | int | str | Series) -> Series:
         return self.ge(other)
 
     def gt(self, other) -> Series:

tests/system/small/operations/test_datetimes.py

@@ -310,9 +310,8 @@ def test_dt_floor(scalars_dfs, col_name, freq):
 def test_dt_compare_coerce_str_datetime(scalars_dfs):
     scalars_df, scalars_pandas_df = scalars_dfs
     bf_series: bigframes.series.Series = scalars_df["datetime_col"]
-    # TODO(b/340878286): fix type error
-    bf_result = (bf_series >= "2024-01-01").to_pandas()  # type: ignore
 
+    bf_result = (bf_series >= "2024-01-01").to_pandas()
     pd_result = scalars_pandas_df["datetime_col"] >= pd.to_datetime("2024-01-01")
 
     # pandas produces pyarrow bool dtype