CLN: removing get_stargets from DatetimeEngine

pandas/_libs/index.pyx

@@ -492,14 +492,6 @@ cdef class DatetimeEngine(Int64Engine):
         except KeyError:
             raise KeyError(val)
 
-    def get_stargets(self, ndarray targets) -> set:
-        stargets = set(targets)
-        # account for NaTs
-        if -1 not in stargets and isnaobj(targets).any():
-            stargets.add(-1)
-
-        return stargets
-
     def get_indexer_non_unique(self, ndarray targets):
         # we may get datetime64[ns] or timedelta64[ns], cast these to int64
         return super().get_indexer_non_unique(targets.view("i8"))

pandas/tests/indexes/test_indexing.py

@@ -267,8 +267,8 @@ def test_getitem_deprecated_float(idx):
     "idx,targets",
     [
         (Index([]), np.array([None])),
+        (Index([]), np.array([NaT])),
         (Float64Index([]), np.array([np.nan])),
-        (DatetimeIndex([]), np.array([NaT])),
     ],
 )
 def test_get_stargets(idx, targets):
@@ -278,12 +278,7 @@ def test_get_stargets(idx, targets):
 
 @pytest.mark.parametrize(
     "idx,val,expected",
-    [
-        (Index([]), None, -1),
-        (Int64Index([]), 1, 1),
-        (Float64Index([]), np.nan, -1),
-        (DatetimeIndex([]), NaT, -1),
-    ],
+    [(Index([]), None, -1), (Int64Index([]), 1, 1), (Float64Index([]), np.nan, -1)],
 )
 def test_convert_val_if_nan(idx, val, expected):
     # GH 35392