Remove additional uses of BIPMapping

There were still two locations where the BIPMapping pass was being used.
First the dedicated unit tests, and then also import redirects for the
docs and easier access. This commit removes these locations so nothing
left is using the BIPMapping pass.

qiskit/transpiler/passes/__init__.py

@@ -45,7 +45,6 @@
    LookaheadSwap
    StochasticSwap
    SabreSwap
-   BIPMapping
    Commuting2qGateRouter
 
 Basis Change
@@ -199,7 +198,6 @@
 from .routing import LookaheadSwap
 from .routing import StochasticSwap
 from .routing import SabreSwap
-from .routing import BIPMapping
 from .routing import Commuting2qGateRouter
 
 # basis change

qiskit/transpiler/passes/routing/__init__.py

@@ -17,6 +17,5 @@
 from .lookahead_swap import LookaheadSwap
 from .stochastic_swap import StochasticSwap
 from .sabre_swap import SabreSwap
-from .bip_mapping import BIPMapping
 from .commuting_2q_gate_routing.commuting_2q_gate_router import Commuting2qGateRouter
 from .commuting_2q_gate_routing.swap_strategy import SwapStrategy