Multiple buffers, duplicate URIs?

I came across a file recently containing three buffers, all sharing the same URI:

```jsonc
"buffers": [
{
"uri": "glTF.bin",
"byteLength": 8160
},
{
"uri": "glTF.bin",
"byteLength": 8160
},
{
"uri": "glTF.bin",
"byteLength": 8160
}
],
```

No validation errors were found, and viewers I tested (three.js, babylon.js, playcanvas) seemed fine, but it did break processing in glTF Transform, which tried to overwrite the buffer repeatedly. The file also contained valid buffer views pointing to each buffer.

My impression is that this is suboptimal, but technically valid, does that seem correct?

No source files or tests are named. Start by checking the glTF buffer schema and validation rules, then compare the duplicate-URI case with the behavior reported for glTF Transform and the tested viewers; done means establishing whether the file is valid and what specification or validation change, if any, is required.

Written by the indexing model from the issue text.