Feature Freeze Exception: Update opendht to 3.0.0

opendht 3.0.0 contains many bug fixes and improvements over the currently packaged 2.4.12, and it would be great if an exception could be granted to upload 3.0.0 to mantic.

The reason a feature freeze exception is required is due to the SONAME bump due to upstream switching a few function signatures in their API to use an improved logging system.

As of now, the only reverse dependency for this library is jami (ring), which has a new version compatible with the opendht API change already released and ready. The latest release of jami, in turn, also includes many bug fixes (including some security fixes) and improvements.

I maintain both of these packages in Debian as a Debian Maintainer, both up-to-date in Debian unstable with latest upstream release; and having tested and used them myself, I believe the latest version of both packages to be in good shape for inclusion in mantic's universe.

opendht upstream release notes since 2.4.12:

v2.5.0

- dht: improved transmission of large amounts of values (>64 KB) for a single key, by transmitting them in separate messages with independent retransmission logic
- docker: added official Alpine Linux-based images, much lighter than Ubuntu-based images (about 30 MB vs 800 MB)
- build/cmake: removed OPENDHT_STATIC and OPENDHT_SHARED options. Use the standard BUILD_SHARED_LIBS option instead
- build/cmake: removed OPENDHT_TESTS option. Use the standard BUILD_TESTING option instead
- build/cmake: now using CTest
- build/meson: added experimental support for the Meson build system
- build/autotools: the Autotools build system is now deprecated and shall be removed when Meson support is considered stable

v2.6.0

- dht: added early announce/listen mechanism, significantly reducing the time taken for the first values to be published or received for a new search, without major trade-off.
- dht: fixed an issue that was causing invalid transaction IDs to be occasionally used
- dht: changed user agent to "o2"
- dhtinterface: added setOnPublicAddressChanged to listen for public address changes
- dhtrunner: added Context::publicAddressChangedCb to make use of the new API
- log: new logger API using {fmt}
- http: added static method Request::url_encode to encode url parameters.
- docker: Alpine image now based on Alpine 3.18
- build/meson: build dhtchat, dhtscanner

v2.6.0.4

- Fix Python binding with latest Cython version

v3.0.0

- Bump SONAME due to recent logging API change