Bump pg and @types/pg (#267)

Bumps [pg](https://github.com/brianc/node-postgres/tree/HEAD/packages/pg) and [@types/pg](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/pg). These dependencies needed to be updated together.

Updates `pg` from 8.6.0 to 8.12.0
- [Changelog](https://github.com/brianc/node-postgres/blob/master/CHANGELOG.md)
- [Commits](https://github.com/brianc/node-postgres/commits/[email protected]/packages/pg)

Updates `@types/pg` from 7.14.11 to 8.11.6
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/pg)

---
updated-dependencies:
- dependency-name: pg
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: "@types/pg"
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>