v2.28.0

This is a major Erlang and Buildroot update. This updates from Erlang/OTP 27 to
Erlang/OTP 28.

• Changes

  • Remove unneeded call to rngd and the rng-tools package. This was
    formerly needed to provide entropy to Linux during initialization.

• Package updates

  • nerves_system_br v1.32.3 release notes
  • Linux 6.12.34

• Updated dependencies

  • Erlang/OTP 28.1.1
  • Buildroot 2025.05.2