Fix the comment in intro.py example

[poojarao8]

The comments preceding the qubit = cudaq.qubit() referring to qalloc are inconsistent with the line of the code.

# Next, we can allocate qubits to the kernel via `qalloc(qubit_count)`.
# An empty call to `qalloc` will return a single qubit.
qubit = cudaq.qubit()