Update CODEOWNERS for spreading review responsibility (#24332)

- Add bangtianliu to LinalgExt since he's been contributing new
LinalgExt ops and transformations.
- Add a new `Codegen/**/*Vector*` category and add myself and active
owners and reviewers to code owners (based on my observation).

Note that the new category is added after `Codegen/Common` so only new
owners will show up on the new matching. From Github's doc:

```
# Order is important; the last matching pattern takes the most
# precedence. When someone opens a pull request that only
# modifies JS files, only @js-owner and not the global
# owner(s) will be requested for a review.
*.js    @js-owner #This is an inline comment.
```

It adds the owners to all vectorization and vector transformations,
except VectorExt (which is a later rule that owned by Groverkss).