chore(deps): bump pg from 8.7.1 to 8.7.3

Bumps [pg](https://github.com/brianc/node-postgres/tree/HEAD/packages/pg) from 8.7.1 to 8.7.3.
- [Release notes](https://github.com/brianc/node-postgres/releases)
- [Changelog](https://github.com/brianc/node-postgres/blob/master/CHANGELOG.md)
- [Commits](https://github.com/brianc/node-postgres/commits/pg@8.7.3/packages/pg)

---
updated-dependencies:
- dependency-name: pg
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]