Bump MAX_VALUES_CHOICE_PARAM from 1000 to 1001 (#5116)

Summary:

 ## Summary:
Bump `MAX_VALUES_CHOICE_PARAM` from 1000 to 1001 in Ax `ChoiceParameter` to fix GitHub issue facebook/Ax #5108.

Users commonly want to split [0, 1] in 0.001 steps, yielding 1001 elements. The previous limit of 1000 blocked this natural use case. Updated the constant in `parameter.py` and adjusted 3 test values in `test_parameter.py` to match the new limit.

Internal
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Reviewed By: Cesar-Cardoso

Differential Revision: D98747907

Author: Racer Engineer

ax/core/parameter.py

@@ -40,7 +40,7 @@
 # TODO: Do a more comprehensive audit of how floating point precision issues
 # may creep up and implement a more principled fix
 EPS = 1.5e-7
-MAX_VALUES_CHOICE_PARAM = 1000
+MAX_VALUES_CHOICE_PARAM = 1001
 FIXED_CHOICE_PARAM_ERROR = (
     "ChoiceParameters require multiple feasible values. "
     "Please use FixedParameter instead when setting a single possible value."

ax/core/tests/test_parameter.py

@@ -490,17 +490,17 @@ def test_MaxValuesValidation(self) -> None:
         ChoiceParameter(
             name="x",
             parameter_type=ParameterType.INT,
-            values=list(range(999)),
+            values=list(range(1000)),
         )
         with self.assertRaisesRegex(
             UserInputError,
-            "`ChoiceParameter` with more than 1000 values is not supported! Use a "
+            "`ChoiceParameter` with more than 1001 values is not supported! Use a "
             "`RangeParameter` instead.",
         ):
             ChoiceParameter(
                 name="x",
                 parameter_type=ParameterType.INT,
-                values=list(range(1001)),
+                values=list(range(1002)),
             )
         # With bypass_cardinality_check=True, this should not raise an error.
         p = ChoiceParameter(