Erlang/OTP 28 compatibility

[l2dy]

As https://openriak.github.io/riak/InstallAndStartGuide.html states:

The Erlang/OTP team are only committed to fixing issues in the three most recent major versions of Erlang.

Since OTP 29 was released in May 2026, OTP 26 has entered its "end of life" stage, so compatibility with a newer major version of Erlang is required to get OTP bug fixes.

[martinsumner]

The openriak-4.0 branch is OTP 28 compliant. There is a project to make this a release candidate, with the expectation that the release candidate will be ready within six months.

The intention is to stay aligned with supported OTP releases from that point going forward (after several years of playing catch-up).