Model UV is not limited to 0-16, bleeding texture atlas

See title.

Model UV mappings aren't limited to 0-16 values, allowing them to bleed the texture sheet.

Steps to reproduce:

1. Create a resource pack with the file assets/minecraft/models/block/cube.json with

   {
       "parent": "block/block",
       "elements": [
           {   "from": [ 0, 0, 0 ],
               "to": [ 16, 16, 16 ],
               "faces": {
                   "down":  { "uv": [-16, -16, 32, 32], "texture": "#down", "cullface": "down" },
                   "up":    { "uv": [-16, -16, 32, 32], "texture": "#up", "cullface": "up" },
                   "north": { "uv": [-16, -16, 32, 32], "texture": "#north", "cullface": "north" },
                   "south": { "uv": [-16, -16, 32, 32], "texture": "#south", "cullface": "south" },
                   "west":  { "uv": [-16, -16, 32, 32], "texture": "#west", "cullface": "west" },
                   "east":  { "uv": [-16, -16, 32, 32], "texture": "#east", "cullface": "east" }
               }
           }
       ]
   }

2. Enable the resource pack

3. Observe how each block now consists of 9 different textures

Expected behavior:

Either one of the following:

• The model fails to process, and will instead show a missing texture for the entire element face.

• The texture applied will repeat itself (eg showing stone textures 9 times, rather than once + 8 others). (This is the preferred solution, as that allows creating a repeating texture without having to duplicate elements or make the texture include itself multiple times.) This solution will also fix MC-246230 instantly, rather than make it dump missing textures, requiring a sepate fix.