Deprecate CheckConn in favor of Ping

conn.go

@@ -382,11 +382,9 @@ func quoteIdentifier(s string) string {
 	return `"` + strings.ReplaceAll(s, `"`, `""`) + `"`
 }
 
-// Ping executes an empty sql statement against the *Conn
-// If the sql returns without error, the database Ping is considered successful, otherwise, the error is returned.
+// Ping delegates to the underlying *pgconn.PgConn.Ping.
 func (c *Conn) Ping(ctx context.Context) error {
-	_, err := c.Exec(ctx, ";")
-	return err
+	return c.pgConn.Ping(ctx)
 }
 
 // PgConn returns the underlying *pgconn.PgConn. This is an escape hatch method that allows lower level access to the