Geoipsets

- Add official Python v3.13 support
- Drop official Python v3.8 support. It is now EOL, although still works fine.
- Support newer Maxmind authentication scheme and download URLs. **This is a breaking change.** See below. (Thanks sh0rch .)
- The bash version now accepts environment variables to control which sets are generated (Thanks sh0rch .)

Maxmind have moved to a new authentication scheme and new download URLs. This version of geoipsets switches to using this mechanism and effectively drops support for older license keys. Anyone using Maxmind should:

1. Log in to their Maxmind account and generate a new license key.
2. Update geoipsets.conf to set both the account-id and license-key as show in the [example](https://github.com/chr0mag/geoipsets/blob/main/python/geoipsets.conf#L33)

- Add python 3.12 support. No code changes required.
- Github Actions integration tests are now run automatically once a week to build all `geoipsets` and load them into both `nftables` and `ipset/iptables`.

Python 3.11 support has now been tested. No code changes required.

- 50% performance improvement when building `dbip` sets only for `nftables`. See issue 25 and PR 27 .
- Fix an edge case where a new run of `geoipsets` uses a different configuration. Existing sets that will not be re-generated as part of the new run will now be kept instead of deleted.

- Significant performance gains when generating the `MaxMind` datasets. See issue 16 and PR 24 .
- The `dbip` download checksum is now validated. This includes the addtition of `--checksum/--no-checksum` flags. See issue 12 and PR 22 .
- Automatic calculation of `ipset` `maxelem` to avoid issues when a set contains more elements than the `ipset` default. See PR 20. Thanks to johnmave126 .
- Improved security for the example systemd unit file. See issue 18 and PR 21 .

- adds support for Python 3.10
- fixes issue 15