Add optimization_level=0 to transpiler for compiling dynamic circuits (#2000)

``id`` gate was removed by transpiler called from aer_compiler without optimization_level for dynamic circuits.
This commits adds ``optimization_level=0`` to avoid removing id gates

Author: doichanj

qiskit_aer/backends/aer_compiler.py

@@ -99,7 +99,9 @@ def compile(self, circuits, basis_gates=None, optypes=None):
                 circuit = self._inline_initialize(circuit, compiled_optypes[idx])
                 if self._is_dynamic(circuit, compiled_optypes[idx]):
                     compiled_circ = transpile(
-                        self._inline_circuit(circuit, None, None), basis_gates=basis_gates
+                        self._inline_circuit(circuit, None, None),
+                        basis_gates=basis_gates,
+                        optimization_level=0,
                     )
                     compiled_circuits.append(compiled_circ)
                     # Recompute optype for compiled circuit

releasenotes/notes/fix_transpiler_lvl_for_dynamic_circuit-4ead3b497bbcc632.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    For dynamic circuits, aer_compiler calls transpiler without optimizaiton
+    level. Because id gates are removed by transpiler, noise applied id gates
+    did not work correctly. This fix adds optimization_level=0 not to remove
+    id gates of dynamic circuits