Rewrite code to avoid disabling B909

backend/src/hatchling/metadata/spec.py

@@ -169,24 +169,27 @@ def project_metadata_from_core_metadata(core_metadata: str) -> dict[str, Any]:
                 continue
 
             markers = req.marker._markers  # noqa: SLF001
+            index = -1
             for i, marker in enumerate(markers):
                 if isinstance(marker, tuple):
                     left, _, right = marker
                     if left.value == 'extra':
                         extra = right.value
-                        del markers[i]  # noqa: B909
-                        # If there was only one marker then there will be an unnecessary
-                        # trailing semicolon in the string representation
-                        if not markers:
-                            req.marker = None
-                        # Otherwise we need to remove the preceding `and` operation
-                        else:
-                            del markers[i - 1]
-
                         optional_dependencies.setdefault(extra, []).append(str(req))
+                        index = i
                         break
             else:
                 dependencies.append(str(req))
+            if index >= 0:
+                del markers[index]
+                index -= 1
+                # We need to remove the preceding `and` operation...
+                if index >= 0:
+                    del markers[index]
+                # ...unless there was only one marker, in which case there will be
+                # an unnecessary trailing semicolon in the string representation.
+                else:
+                    req.marker = None
 
         metadata['dependencies'] = dependencies