[stubsabot] Bump pytz to 2026.5

Release: https://pypi.org/pypi/pytz/2026.5
Homepage: http://pythonhosted.org/pytz
Repository: https://github.com/stub42/pytz
Typeshed stubs: https://github.com/python/typeshed/tree/main/stubs/pytz

If stubtest fails for this PR:
- Leave this PR open (as a reminder, and to prevent stubsabot from opening another PR)
- Fix stubtest failures in another PR, then close this PR

Author: stubsabot

stubs/pytz/METADATA.toml

@@ -1,3 +1,3 @@
 # This is a mirror of https://git.launchpad.net/pytz/tree, see https://pythonhosted.org/pytz/#latest-versions
-version = "2026.4"
+version = "2026.5"
 upstream-repository = "https://github.com/stub42/pytz"