Simplify parsed markers exactly once

No need to do it in every recursive sub-call

src/poetry/core/version/markers.py

@@ -696,7 +696,9 @@ def parse_marker(marker: str) -> BaseMarker:
     return markers
 
 
-def _compact_markers(tree_elements: Tree, tree_prefix: str = "") -> BaseMarker:
+def _compact_markers(
+    tree_elements: Tree, tree_prefix: str = "", top_level: bool = True
+) -> BaseMarker:
     from lark import Token
 
     # groups is a disjunction of conjunctions
@@ -711,7 +713,9 @@ def _compact_markers(tree_elements: Tree, tree_prefix: str = "") -> BaseMarker:
             continue
 
         if token.data == "marker":
-            sub_marker = _compact_markers(token.children, tree_prefix=tree_prefix)
+            sub_marker = _compact_markers(
+                token.children, tree_prefix=tree_prefix, top_level=False
+            )
             groups[-1].append(sub_marker)
 
         elif token.data == f"{tree_prefix}item":
@@ -729,10 +733,15 @@ def _compact_markers(tree_elements: Tree, tree_prefix: str = "") -> BaseMarker:
         elif token.data == f"{tree_prefix}BOOL_OP" and token.children[0] == "or":
             groups.append([])
 
-    # Combine and simplify the groups.
+    # Combine the groups.
     sub_markers = [MultiMarker(*group) for group in groups]
     union = MarkerUnion(*sub_markers)
 
+    # This function calls itself recursively. In the inner calls we don't perform any
+    # simplification, instead doing it all only when we have the complete marker.
+    if not top_level:
+        return union
+
     conjunction = cnf(union)
     if not isinstance(conjunction, MultiMarker):
         return conjunction