running PG e2e tests on Postgres 12 too

.github/workflows/flow-pg12.yml

@@ -0,0 +1,78 @@
+name: Flow build and test [Postgres 12]
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+jobs:
+  flow_test:
+    strategy:
+      matrix:
+        runner: [ubicloud-standard-8-ubuntu-2204-arm]
+    runs-on: ${{ matrix.runner }}
+    timeout-minutes: 30
+    services:
+      pg_cdc:
+        image: imresamu/postgis:12-3.4-alpine
+        ports:
+          - 7132:5432
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: postgres
+        options: >-
+          --name pg_cdc
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+    steps:
+      - name: checkout sources
+        uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v4
+        with:
+          go-version: ">=1.21.0"
+          cache-dependency-path: flow/go.sum
+
+      - name: install gotestsum
+        run: |
+          go install gotest.tools/gotestsum@latest
+
+      - name: install lib-geos
+        run: |
+          sudo apt-get update
+          sudo apt-get install libgeos-dev
+
+      - name: download go modules
+        run: |
+          go mod download
+        working-directory: ./flow
+
+      - name: create hstore extension, increase logical replication limits, and setup catalog database
+        run: >
+          docker exec pg_cdc psql -h localhost -p 5432 -U postgres -c "CREATE EXTENSION hstore;"
+          -c "ALTER SYSTEM SET wal_level=logical;"
+          -c "ALTER SYSTEM SET max_replication_slots=192;"
+          -c "ALTER SYSTEM SET max_wal_senders=256;"
+          -c "ALTER SYSTEM SET max_connections=2048;" &&
+          (cat ../nexus/catalog/migrations/V{?,??}__* | docker exec -i pg_cdc psql -h localhost -p 5432 -U postgres) &&
+          docker restart pg_cdc
+        working-directory: ./flow
+        env:
+          PG_CDC: empty
+          PGPASSWORD: postgres
+
+      - name: run tests
+        run: |
+          gotestsum --format testname -- -p 8 ./... -timeout 600s
+        working-directory: ./flow/e2e/postgres
+        env:
+          PEERDB_CATALOG_HOST: localhost
+          PEERDB_CATALOG_PORT: 7132
+          PEERDB_CATALOG_USER: postgres
+          PEERDB_CATALOG_PASSWORD: postgres
+          PEERDB_CATALOG_DATABASE: postgres
+          PEERDB_CDC_IDLE_TIMEOUT_SECONDS: 10