Log explorer: Height of dropdowns and inputs should be the same by default
## Problem
We patched the heights of logs page to `gl-h-32` because by default:
- Our filtered search input has a height of exactly `32px` (2rem).
- Out dropdowns have a default height of `35px` which is inherited from boostrap's default styles.
### Goal
Update to new dropdowns so the entire control matches the Pajamas design system
## Original Discussion
The following discussion from https://gitlab.com/gitlab-org/gitlab/-/merge_requests/23837 should be addressed:
- [ ] @mrincon started a [discussion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/23837#note_279961115): (+2 comments)
> /cc @nadia_sotnikova
issue