Major overhaul on acceptance test infrastructure and ci pipeline

- Intent is to deploy this to the shared foundational infrastructure ci instance
- As there is no longer a long lived bosh director, the acceptance tests now run in a bosh-lite environment directly in the CI container
- CI has jobs for acceptance tests, automated weekly bumps for golang packages, automated bumps of postgres packages, a job to cut a final release, and a job that detects postgres 15 package bumps and automatically triggers a release
- All other CI pipelines and tasks have been removed
- Acceptance tests have been updated to go mod and dependencies have been vendored
- I've removed the "old" concept from the versions.yml and instead changed the helper
  to use the release two versions back as the old one. Not 100% sure this is correct
  behavior (and may cause problems due to v45 being broken), but it seems like
  testing n-2 to current will always catch problems caused by a major postgres bump.

Author: Joseph Palermo

.gitignore

@@ -23,6 +23,5 @@
 /releases/*.tgz
 /src/acceptance-tests/bin
 /src/acceptance-tests/pkg
-/src/acceptance-tests/vendor
 /tags
 pgats_config.yml

ci/configure.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -eu
+
+dir="$(dirname "$0")"
+
+fly -t "${CONCOURSE_TARGET:-bosh}" set-pipeline -p postgres-release -c "$dir/pipeline.yml"