Remove imprecise model for list()

Author: owen-mc

python/ql/lib/semmle/python/frameworks/Stdlib.qll

@@ -4244,15 +4244,9 @@ module StdlibPrivate {
         )
         // TODO: Once we have DictKeyContent, we need to transform that into ListElementContent
       ) and
-      (
-        // Element content is mutated into list element content
-        output = "ReturnValue.ListElement" and
-        preservesValue = true
-        or
-        // Since list content is imprecise, we also taint the list.
-        output = "ReturnValue" and
-        preservesValue = false
-      )
+      // Element content is mutated into list element content
+      output = "ReturnValue.ListElement" and
+      preservesValue = true
       or
       input = "Argument[0]" and
       output = "ReturnValue" and