removed try/except clause

Author: NoureldinYosri

cirq-core/cirq/ops/linear_combinations_test.py

@@ -1136,11 +1136,8 @@ def test_paulisum_validation():
     ld = cirq.LinearDict({key: 2.0})
     assert cirq.PauliSum(ld) == cirq.PauliSum.from_pauli_strings([2 * cirq.X(q[0])])
 
-    try:
-        ps = cirq.PauliSum()
-        ps += cirq.I(cirq.LineQubit(0))
-    except:
-        raise Exception("Failed to add identity to PauliSum.")
+    ps = cirq.PauliSum()
+    ps += cirq.I(cirq.LineQubit(0))
     assert ps == cirq.PauliSum(cirq.LinearDict({frozenset(): complex(1)}))