Import Postgres driver support for the psql indexer (backport). (#7057)

I accidentally omitted this from the backport in #6906.
Fixes #7043.

CHANGELOG_PENDING.md

@@ -25,3 +25,5 @@ Friendly reminder, we have a [bug bounty program](https://hackerone.com/tendermi
 ### IMPROVEMENTS
 
 ### BUG FIXES
+
+- [\#7057](https://github.com/tendermint/tendermint/pull/7057) Import Postgres driver support for the psql indexer (@creachadair).

node/node.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"net"
 	"net/http"
-	_ "net/http/pprof" // nolint: gosec // securely exposed on separate, optional port
 	"strings"
 	"time"
 
@@ -50,6 +49,10 @@ import (
 	"github.com/tendermint/tendermint/types"
 	tmtime "github.com/tendermint/tendermint/types/time"
 	"github.com/tendermint/tendermint/version"
+
+	_ "net/http/pprof" // nolint: gosec // securely exposed on separate, optional port
+
+	_ "github.com/lib/pq" // provide the psql db driver
 )
 
 //------------------------------------------------------------------------------