`has_fixed` is missing from the dimension field in the `Join Game` client bound packet

Versions

• server: vanilla 1.17.1

Detailed description of a problem

According to https://wiki.vg/Protocol the Join Game packets Dimension Type should include a property fixed_time if the doDayLightCycle is set to false. However there is not such a property in the client packet as of now.

Current code

This is the current output of NMP dimension field.

{
  piglin_safe: { type: 'byte', value: 0 },
  natural: { type: 'byte', value: 1 },
  ambient_light: { type: 'float', value: 0 },
  infiniburn: { type: 'string', value: 'minecraft:infiniburn_overworld' },
  respawn_anchor_works: { type: 'byte', value: 0 },
  has_skylight: { type: 'byte', value: 1 },
  bed_works: { type: 'byte', value: 1 },
  effects: { type: 'string', value: 'minecraft:overworld' },
  has_raids: { type: 'byte', value: 1 },
  logical_height: { type: 'int', value: 256 },
  coordinate_scale: { type: 'double', value: 1 },
  min_y: { type: 'int', value: 0 },
  has_ceiling: { type: 'byte', value: 0 },
  ultrawarm: { type: 'byte', value: 0 },
  height: { type: 'int', value: 256 }
}

Expected behavior

Should include fixed_time.

{
 fixed_time: { type: 'long', value: 123456 }
}

Start at the Join Game client-bound packet entry point and inspect how its dimension field is decoded or represented. Compare the dimension properties with the linked wiki.vg protocol description; done means the field includes fixed_time as a long value when required, with the relevant packet behavior covered by an existing test if available.