Revise code comment and news

Author: danny0838

Lib/zipfile/__init__.py

@@ -542,8 +542,7 @@ def FileHeader(self, zip64=None):
             file_size = self.file_size
 
         # Strip extra fields that should not exist in the local entry or should
-        # be determined later. (self.extra can be read from central directory
-        # when read in append mode)
+        # be determined later.
         extra = _Extra.strip(self.extra, (
             0x0001,  # Zip64
             0x0017,  # Strong Encryption Header

Misc/NEWS.d/next/Library/2026-06-29-03-43-41.gh-issue-152486.kASYh8.rst

@@ -1,4 +1,4 @@
-Fix an issue where duplicated Zip64 extra fields or other invalid
-fields were written if :attr:`ZipInfo.extra <zipfile.ZipInfo.extra>`
-already contained them (which could be read from central directory in
-append mode).
+Fix an issue where duplicated Zip64 extra fields or other improper
+fields were written to the local file entry if
+:attr:`ZipInfo.extra <zipfile.ZipInfo.extra>` contained them.
+