build(deps): bump tree-sitter-haskell from 8a99848 to 6b5ec20

Bumps [tree-sitter-haskell](https://github.com/tree-sitter/tree-sitter-haskell) from `8a99848` to `6b5ec20`.
- [Commits](tree-sitter/tree-sitter-haskell@8a99848...6b5ec20)

---
updated-dependencies:
- dependency-name: tree-sitter-haskell
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>