Small fix for an overly aggressive warning (#6707)

**Context:**
Was raising a warning too aggressively.

**Description of the Change:**
Small change to make sure using numpy with autograd/jax doesn't raise a
warning.

**Benefits:**

**Possible Drawbacks:**

**Related GitHub Issues:**

doc/releases/changelog-dev.md

@@ -229,6 +229,7 @@ such as `shots`, `rng` and `prng_key`.
 
 * Added JAX support for the differentiable Hartree-Fock workflow.
   [(#6096)](https://github.com/PennyLaneAI/pennylane/pull/6096)
+  [(#6707)](https://github.com/PennyLaneAI/pennylane/pull/6707)
 
 * Added functions and dunder methods to add and multiply Resources objects in series and in parallel.
   [(#6567)](https://github.com/PennyLaneAI/pennylane/pull/6567)

pennylane/qchem/molecule.py

@@ -144,7 +144,16 @@ def __init__(
                     for i, c in enumerate(coeff)
                 ]
 
-        if len(set(qml.math.get_deep_interface(x) for x in [coordinates, alpha, coeff])) > 1:
+        if (
+            len(
+                {
+                    qml.math.get_deep_interface(x)
+                    for x in [coordinates, alpha, coeff]
+                    if qml.math.get_deep_interface(x) != "numpy"
+                }
+            )
+            > 1
+        ):
             warnings.warn(
                 "The parameters coordinates, coeff, and alpha are not of the same interface. Please use the same interface for all 3 or there may be unintended behavior.",
                 UserWarning,