[v11.0.x] Revert "Postgres: Switch the datasource plugin from lib/pq to pgx (#8… (#85517)

Revert "Postgres: Switch the datasource plugin from lib/pq to pgx (#8… (#85509)

Revert "Postgres: Switch the datasource plugin from lib/pq to pgx (#83768)"

This reverts commit ecd6de826a.

(cherry picked from commit 8159e1db3a)

Co-authored-by: Gábor Farkas <gabor.farkas@gmail.com>

go.mod

@@ -470,8 +470,6 @@ require (
 	github.com/xwb1989/sqlparser v0.0.0-20180606152119-120387863bf2 // @grafana/grafana-app-platform-squad
 )
 
-require github.com/jackc/pgx/v5 v5.5.5 // @grafana/oss-big-tent
-
 require github.com/getkin/kin-openapi v0.120.0 // @grafana/grafana-as-code
 
 require (
@@ -487,9 +485,6 @@ require (
 	github.com/go-playground/validator/v10 v10.14.0 // indirect
 	github.com/hashicorp/go-uuid v1.0.3 // indirect
 	github.com/invopop/jsonschema v0.12.0 // indirect
-	github.com/jackc/pgpassfile v1.0.0 // indirect
-	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect
-	github.com/jackc/puddle/v2 v2.2.1 // indirect
 	github.com/jcmturner/aescts/v2 v2.0.0 // indirect
 	github.com/jcmturner/dnsutils/v2 v2.0.0 // indirect
 	github.com/jcmturner/gofork v1.7.6 // indirect