remove unnecessary ServiceLoader load logic

[kaibocai]

Issue describing the changes in this PR

remove the unnecessary ServiceLoader load logic. It's duplicate logics as create db connection will call the spi logics.

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes should not be added to the release notes for the next release
  • Otherwise: I've added my notes to release_notes.md
• My changes do not need to be backported to a previous version
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• I have added all required tests (Unit tests, E2E tests)

Additional information

Additional PR information

[kaibocai]

Hi @trask ,
@amamounelsayed mention that he worked with you on adding this loadDriver logics. We just found it's not necessary as when customer create the DB connection, the spi logics will be executed, example here. So the logic seems doing the duplicate works.