Remove stale condition from assert_controlled_and_controlled_by_ident…

…ical test (#5391)

* Remove stale condition from assert_controlled_and_controlled_by_identical test

* Fix lint errors

cirq-core/cirq/testing/consistent_controlled_gate_op.py

@@ -14,7 +14,7 @@
 
 from typing import Sequence, Optional, Union, Collection
 
-from cirq import protocols, devices, ops
+from cirq import devices, ops
 
 
 def assert_controlled_and_controlled_by_identical(
@@ -39,10 +39,6 @@ def _assert_gate_consistent(
     num_controls: int,
     control_values: Optional[Sequence[Union[int, Collection[int]]]],
 ) -> None:
-    if isinstance(gate, ops.DensePauliString) and protocols.is_parameterized(gate):
-        # Parameterized `DensePauliString`s cannot be applied to qubits to produce valid operations.
-        # TODO: This behavior should be fixed (https://github.com/quantumlib/Cirq/issues/4508)
-        return None
     gate_controlled = gate.controlled(num_controls, control_values)
     qubits = devices.LineQid.for_gate(gate_controlled)
     control_qubits = qubits[:num_controls]