• /geoip/updates/metadata which is responsible for getting information about
  a database edition.
• /geoip/databases/{edition-id}/download which is responsible for downloading
  the content of a database edition. This new endpoint redirects downloads to R2
  presigned URLs, so systems running geoipupdate need to be able to
  reach
  mm-prod-geoip-databases.a2649acb697e2c09b632799562c076f2.r2.cloudflarestorage.com
  in addition to updates.maxmind.com.

geoipupdate now supports configuration via environment variables. Any
configuration set this way will override any value from the config file,
but still be overridden by any associated command line option (if any).
The following new environment variables are supported:

• GEOIPUPDATE_ACCOUNT_ID
• GEOIPUPDATE_ACCOUNT_ID_FILE
• GEOIPUPDATE_CONF_FILE
• GEOIPUPDATE_DB_DIR
• GEOIPUPDATE_EDITION_IDS
• GEOIPUPDATE_HOST
• GEOIPUPDATE_LICENSE_KEY
• GEOIPUPDATE_LICENSE_KEY_FILE
• GEOIPUPDATE_LOCK_FILE
• GEOIPUPDATE_PARALLELISM
• GEOIPUPDATE_PRESERVE_FILE_TIMES
• GEOIPUPDATE_PROXY
• GEOIPUPDATE_PROXY_USER_PASSWORD
• GEOIPUPDATE_RETRY_FOR
• GEOIPUPDATE_VERBOSE

Changed the signature of NewConfig in pkg/geoipupdate to no longer accept
a positional config file path argument, which can now be passed in using the
option from WithConfigFile along with the other optional parameters.

geoipupdate and NewConfig no longer require a config file to exist.

The --stack-trace flag has been removed. This flag has been broken since
4.11.0.