[mlir][Vector] Remove duplicated test cases (#70029)

All the deleted test cases use identical matmul trait (only the suffix
in the name changes):

```mlir
  affine_map<(m, n, k) -> (m, k)>,
  affine_map<(m, n, k) -> (k, n)>,
  affine_map<(m, n, k) -> (n, m)>
]
  indexing_maps = #matmat_accesses_n,
  iterator_types = ["parallel", "parallel", "reduction"]
}
```

This is identical to `#matmat_trait_4` and that's the one that's
preserved.

0 files changed, 0 insertions, 0 deletions