gh-51067: Spell out ZipFile.repack() keyword arguments

Replace **opts passthrough with the documented keyword-only signature
so help()/inspect show the real parameters and the internal debug=
hook is not reachable from public API.

Author: gpshead

Lib/test/test_zipfile/test_core.py

@@ -1828,15 +1828,15 @@ def test_repack_propagation(self):
             with mock.patch.object(zipfile._ZipRepacker, 'repack') as m_rp, \
                  mock.patch.object(zipfile, '_ZipRepacker', wraps=zipfile._ZipRepacker) as m_zr:
                 zh.repack()
-        m_zr.assert_called_once_with()
+        m_zr.assert_called_once_with(strict_descriptor=True, chunk_size=2**20)
         m_rp.assert_called_once_with(zh, None)
 
         with zipfile.ZipFile(TESTFN, 'a', self.compression) as zh:
             zi = zh.remove(zh.infolist()[0])
             with mock.patch.object(zipfile._ZipRepacker, 'repack') as m_rp, \
                  mock.patch.object(zipfile, '_ZipRepacker', wraps=zipfile._ZipRepacker) as m_zr:
-                zh.repack([zi], strict_descriptor=True, chunk_size=1024)
-        m_zr.assert_called_once_with(strict_descriptor=True, chunk_size=1024)
+                zh.repack([zi], strict_descriptor=False, chunk_size=1024)
+        m_zr.assert_called_once_with(strict_descriptor=False, chunk_size=1024)
         m_rp.assert_called_once_with(zh, [zi])
 
     def test_repack_bytes_before_first_file(self):

Lib/zipfile/__init__.py

@@ -2390,7 +2390,7 @@ def remove(self, zinfo_or_arcname):
 
         return zinfo
 
-    def repack(self, removed=None, **opts):
+    def repack(self, removed=None, *, strict_descriptor=True, chunk_size=2**20):
         """Repack a zip file, removing non-referenced file entries.
 
         The archive must be opened with mode 'a', as mode 'w'/'x' do not
@@ -2410,7 +2410,11 @@ def repack(self, removed=None, **opts):
         with self._lock:
             self._writing = True
             try:
-                _ZipRepacker(**opts).repack(self, removed)
+                repacker = _ZipRepacker(
+                    strict_descriptor=strict_descriptor,
+                    chunk_size=chunk_size,
+                )
+                repacker.repack(self, removed)
             finally:
                 self._writing = False