feat: setting bd when instantiating a quimb circuit

src/qibotn/backends/quimb.py

@@ -1,4 +1,5 @@
 from collections import Counter
+from typing import Optional
 
 import numpy as np
 import quimb as qu
@@ -220,7 +221,9 @@ if not __name__ == "__main__":
             The real part of the expectation value of the Hamiltonian on the given circuit state.
         """
         quimb_circuit = self._qibo_circuit_to_quimb(
-            circuit, quimb_circuit_type=qtn.Circuit
+            circuit, 
+            quimb_circuit_type=qtn.Circuit, 
+            gate_opts={"max_bond": self.max_bond_dimension},
         )
 
         expectation_value = 0.0