[llvm] Remove 'vectorizers' label from PR labeler (PR #67810)

[Vlad Serebrennikov via llvm-commits]

Endilll wrote:

For the reference, here are patterns for `vectorization` label:
https://github.com/Endilll/llvm-project/blob/67a29bf556e2a2fbd0ae520df5f5f88ce76d3969/.github/new-prs-labeler.yml#L56-L58

https://github.com/llvm/llvm-project/pull/67810