Bump pg from 8.5.1 to 8.6.0 in /hedera-mirror-rest (#1858)

Bumps [pg](https://github.com/brianc/node-postgres/tree/HEAD/packages/pg) from 8.5.1 to 8.6.0.
- [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@8.6.0/packages/pg)

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

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

hedera-mirror-rest/package.json

@@ -34,7 +34,7 @@
     "long": "^4.0.0",
     "mathjs": "^9.3.2",
     "node-fetch": "^2.6.1",
-    "pg": "~8.5.1",
+    "pg": "~8.6.0",
     "qs": "^6.10.1",
     "swagger-stats": "^0.95.18",
     "swagger-ui-express": "^4.1.6"