Use a mirror for ISO codes data as upstream is flaky

Author: kovidgoyal

setup/iso_codes.py

@@ -16,7 +16,7 @@
 
 @lru_cache(2)
 def iso_codes_data():
-    URL = 'https://salsa.debian.org/iso-codes-team/iso-codes/-/archive/main/iso-codes-main.zip'
+    URL = 'https://download.calibre-ebook.com/iso-codes.zip'
     return download_securely(URL)