Disable Aer plugin that causes test failures with Qiskit 1.1 (#1456)

This change is a workaround until
Qiskit/qiskit-aer#2142 is released.

test/base.py

@@ -24,6 +24,7 @@
 import testtools
 import uncertainties
 from qiskit.utils.deprecation import deprecate_func
+import qiskit_aer.backends.aerbackend
 
 from qiskit_experiments.framework import (
     ExperimentDecoder,
@@ -33,6 +34,13 @@
 from qiskit_experiments.framework.experiment_data import ExperimentStatus
 from .extended_equality import is_equivalent
 
+
+# Workaround until https://github.com/Qiskit/qiskit-aer/pull/2142 is released
+try:
+    del qiskit_aer.backends.aerbackend.AerBackend.get_translation_stage_plugin
+except AttributeError:
+    pass
+
 # Fail tests that take longer than this
 TEST_TIMEOUT = int(os.environ.get("TEST_TIMEOUT", 60))
 # Use testtools by default as a (mostly) drop in replacement for