gh-139546: Update test_zoneinfo data to 2025c (#139547)

* Commit

* Skip if tzdata version does not match

* Mark as generated

* Update to 2025.3

Author: StanFromIreland

.gitattributes

@@ -88,6 +88,7 @@ Lib/test/certdata/*.pem                             generated
 Lib/test/certdata/*.0                               generated
 Lib/test/levenshtein_examples.json                  generated
 Lib/test/test_stable_abi_ctypes.py                  generated
+Lib/test/test_zoneinfo/data/*.json                  generated
 Lib/token.py                                        generated
 Misc/sbom.spdx.json                                 generated
 Objects/typeslots.inc                               generated

Lib/test/test_zoneinfo/data/update_test_data.py

@@ -120,3 +120,6 @@ def update_test_data(fname: str = "zoneinfo_data.json") -> None:
 
 if __name__ == "__main__":
     update_test_data()
+
+    print("Remember to update the HAS_TZDATA_PKG version requirement in "
+          "test_zoneinfo.py!")