Fix qml.MultiControlledX usage (#1040)

**Context:**
For the operator `qml.MultiControlledX`, two features have been
deprecated long ago and will be removed very soon:
 - `str` input of `control_values`, e.g. `"01"`
- optional arg `control_wires`. Instead, `wires[:-1]` strictly acts as
the control wires.

Somehow deprecated usages have been spotted in lightning master branch,
therefore we would like to fix them asap.

**Description of the Change:**

 - `tests/test_gates.py`, "01" -> [0, 1]
- `tests/lightning_tensor/test_gates_and_expval.py`, based on the
context, the usage `qml.MultiControlledX(wires=[wires[0], wires[1],
wires[3]], control_values=[wires[0], wires[1]])` seems to be mistaking a
`qml.MultiControlledX(wires=[wires[0], wires[1], wires[3]],
control_wires=[wires[0], wires[1]])`. If the guess is correct, we can
fix it by `qml.MultiControlledX(wires=[wires[0], wires[1], wires[3]])`
P.S. direct change to `control_wires` couldn't pass the tests; therefore
we specified `control_values=[0, 1]` which worked; I guess it's made by
a mistake but happen to work, along with adjustments over the
corresponding expected res.

**Benefits:**
Compatibility with PL0.41

**Possible Drawbacks:**

**Related GitHub Issues:**
[sc-81527]
[sc-81795]

---------

Co-authored-by: ringo-but-quantum <[email protected]>
Co-authored-by: Ali Asadi <[email protected]>

.github/CHANGELOG.md

@@ -6,9 +6,12 @@
 
 ### Improvements
 
+* Update `qml.MultiControlledX` tests following the latest updates in PennyLane.
+  [(#1040)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1040)
+
 * Update the minimum required version of PennyLane to `v0.40.0`.
   [(#1033)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1033)
-  
+
 * Merge the `v0.40.0-rc` branch to the master and bump version.
   [(#1038)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1038)
 
@@ -23,7 +26,7 @@
 
 This release contains contributions from (in alphabetical order):
 
-Joseph Lee, Shuli Shu
+Yushao Chen, Joseph Lee, Shuli Shu
 
 ---
 

pennylane_lightning/core/_version.py

@@ -16,4 +16,4 @@
    Version number (major.minor.patch[-label])
 """
 
-__version__ = "0.41.0-dev4"
+__version__ = "0.41.0-dev5"

tests/lightning_tensor/test_gates_and_expval.py

@@ -73,7 +73,7 @@ def circuit_ansatz(params, wires):
         qml.matrix(qml.PauliX([wires[1]])), control_wires=[wires[0]], wires=wires[1]
     )
     qml.DiagonalQubitUnitary(np.array([1, 1]), wires=wires[2])
-    qml.MultiControlledX(wires=[wires[0], wires[1], wires[3]], control_values=[wires[0], wires[1]])
+    qml.MultiControlledX(wires=[wires[0], wires[1], wires[3]], control_values=[0, 1])
     qml.PauliX(wires=wires[1])
     qml.PauliY(wires=wires[2])
     qml.PauliZ(wires=wires[3])

tests/test_gates.py

@@ -89,7 +89,7 @@ def op(op_name):
         "MultiControlledX": [
             qml.MultiControlledX,
             [],
-            {"wires": [0, 1, 2], "control_values": "01"},
+            {"wires": [0, 1, 2], "control_values": [0, 1]},
         ],
         "SingleExcitation": [qml.SingleExcitation, [0.123], {"wires": [0, 1]}],
         "SingleExcitationPlus": [qml.SingleExcitationPlus, [0.123], {"wires": [0, 1]}],