reduce sc_qubits image sizes to improve page load times (#1556)

**Summary:**

This PR reduces some of the image sizes for the `sc_qubits` demo to test
out the impact on `pennylane.ai` page loading performance.

Author: jontoye

_static/demonstration_assets/sc_qubits/LC_circuit.png

@@ -8,7 +8,7 @@
     "executable_stable": true,
     "executable_latest": true,
     "dateOfPublication": "2022-03-22T00:00:00+00:00",
-    "dateOfLastModification": "2025-09-09T17:41:50+00:00",
+    "dateOfLastModification": "2025-09-22T17:41:50+00:00",
     "categories": [
         "Quantum Hardware",
         "Quantum Computing"