Remove duplicate optimization loop in level 3 PassManager (#8785)

For some time (I expect since #6403 but maybe before) we've been running
the optimization loop for optimization level 3 twice for no reason. This
is clearly a mistake as it adds a single extra run of all the optimization
passes since we've already reached a steady state in depth and size by this
point. This is just a waste of time and was unintentional. This commit
removes the unintended duplication.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

qiskit/transpiler/preset_passmanagers/level3.py

@@ -296,8 +296,6 @@ def _unroll_condition(property_set):
             optimization.append(
                 _opt + _unroll_if_out_of_basis + _depth_check + _size_check, do_while=_opt_control
             )
-        opt_loop = _depth_check + _opt + _unroll_if_out_of_basis
-        optimization.append(opt_loop, do_while=_opt_control)
     else:
         optimization = plugin_manager.get_passmanager_stage(
             "optimization", optimization_method, pass_manager_config, optimization_level=3