🚨 fix new ruff warnings

Signed-off-by: burgholzer <burgholzer@me.com>

mqt/qmap/compile.py

@@ -42,9 +42,9 @@ def extract_initial_layout_from_qasm(qasm: str, qregs: list[QuantumRegister]) ->
     for line in qasm.split("\n"):
         if line.startswith("// i "):
             # strip away initial part of line
-            line = line[5:]
+            stripped_line = line[5:]
             # split line into tokens
-            tokens = line.split(" ")
+            tokens = stripped_line.split(" ")
             # convert tokens to integers
             int_tokens = [int(token) for token in tokens]
             # create an empty layout

mqt/qmap/subarchitectures.py

@@ -374,8 +374,8 @@ def __compute_desirable_subarchitectures(self) -> None:
                 des.sort()
                 new_des: set[tuple[int, int]] = set()
                 for j, (n_prime, i_prime) in enumerate(reversed(des)):
-                    j = len(des) - j - 1
-                    if not any((n_prime, i_prime) in self.subarch_order[k] for k in des[:j]):
+                    idx = len(des) - j - 1
+                    if not any((n_prime, i_prime) in self.subarch_order[k] for k in des[:idx]):
                         new_des.add((n_prime, i_prime))
 
                 self.desirable_subarchitectures[(n, i)] = new_des