📝 fix up docs warnings (#338)

## Description

This small PR fixes a couple of warnings rendered in the docs due to a
qiskit update.

## Checklist:

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your pull request will be merged swiftly.
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- [x] The pull request only contains commits that are related to it.
- [x] I have added appropriate tests and documentation.
- [x] I have made sure that all CI jobs on GitHub pass.
- [x] The pull request introduces no new warnings and follows the
project's style guidelines.

Signed-off-by: burgholzer <burgholzer@me.com>

docs/source/CompilationFlowVerification.ipynb

@@ -53,7 +53,7 @@
     "circ.x(range(2))\n",
     "circ.h(range(2))\n",
     "circ.measure_all()\n",
-    "circ.draw(output=\"mpl\")"
+    "circ.draw(output=\"mpl\", style=\"iqp\")"
    ]
   },
   {
@@ -86,7 +86,7 @@
     "# compile circuit to 5-qubit London Architecture\n",
     "optimization_level = 1\n",
     "circ_comp = transpile(circ, backend=FakeLondon(), optimization_level=optimization_level)\n",
-    "circ_comp.draw(output=\"mpl\", fold=-1)"
+    "circ_comp.draw(output=\"mpl\", fold=-1, style=\"iqp\")"
    ]
   },
   {

docs/source/ParameterizedCircuits.ipynb

@@ -53,7 +53,7 @@
     "qc_lhs.cx(0, 1)\n",
     "qc_lhs.rz(beta, 1)\n",
     "qc_lhs.cx(0, 1)\n",
-    "qc_lhs.draw(output=\"mpl\")"
+    "qc_lhs.draw(output=\"mpl\", style=\"iqp\")"
    ]
   },
   {
@@ -76,7 +76,7 @@
     "qc_rhs.rz(beta, 1)\n",
     "qc_rhs.cx(0, 1)\n",
     "qc_rhs.rz(alpha, 1)\n",
-    "qc_rhs.draw(output=\"mpl\")"
+    "qc_rhs.draw(output=\"mpl\", style=\"iqp\")"
    ]
   },
   {
@@ -120,7 +120,7 @@
     "qc_rhs_err.rz(alpha, 1)\n",
     "qc_rhs_err.cx(0, 1)\n",
     "qc_rhs_err.rz(beta, 1)\n",
-    "qc_rhs_err.draw(output=\"mpl\")"
+    "qc_rhs_err.draw(output=\"mpl\", style=\"iqp\")"
    ]
   },
   {
@@ -148,14 +148,6 @@
    "source": [
     "Check out the [reference documentation](library/VerifyCompilation.rst#mqt.qcec.verify_compilation) documentation for more information."
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "98d4cd4d",
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {

docs/source/Quickstart.ipynb

@@ -24,7 +24,7 @@
     "\n",
     "qc1 = QuantumCircuit(2)\n",
     "qc1.cx(0, 1)\n",
-    "qc1.draw(output=\"mpl\")"
+    "qc1.draw(output=\"mpl\", style=\"iqp\")"
    ]
   },
   {
@@ -41,7 +41,7 @@
     "qc2.cx(1, 0)\n",
     "qc2.h(1)\n",
     "qc2.h(0)\n",
-    "qc2.draw(output=\"mpl\")"
+    "qc2.draw(output=\"mpl\", style=\"iqp\")"
    ]
   },
   {