Better error message for dynamic allocation size when capture is enabled

[paul0403]

Context:
With capture enabled, it was decided that the allocation size can only be static.

However, the current error message just falls through to whatever first error is encountered down the line. For the user this is not very actionable.

qml.capture.enable()

@qml.qnode(qml.device("default.qubit", wires=10))
def circuit(n: int):
    qml.X(0)                        # |10>

    with qml.allocate(n) as q:      # |10> and |0>, 1 dynamically allocated qubit
        qml.X(q[0])                 # |10> and |1>
        qml.CNOT(wires=[q[0], 1])   # |11> and |1>

    return qml.probs(wires=[0, 1])

print(circuit(1))

  File "/home/paul.wang/catalyst_new/catalyst/cat_env/lib/python3.11/site-packages/pennylane/workflow/_capture_qnode.py", line 481, in _extract_qfunc_jaxpr
    raise CaptureError(
pennylane.exceptions.CaptureError: Autograph must be used when Python control flow is dependent on a dynamic variable (a function input). Please ensure that autograph is being correctly enabled with `qml.capture.run_autograph` or disabled with `qml.capture.disable_autograph` or consider using PennyLane native control flow functions like `qml.for_loop`, `qml.while_loop`, or `qml.cond`.

Description of the Change:
Raise a better error message.

Benefits:
Clearer suggestion for user action.

[sc-100475]

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.42%. Comparing base (8ebe766) to head (a318891).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #8381   +/-   ##
=======================================
  Coverage   99.42%   99.42%           
=======================================
  Files         582      582           
  Lines       60902    60905    +3     
=======================================
+ Hits        60551    60554    +3     
  Misses        351      351           

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[dwierichs]

LGTM, just one optional suggestion.