postgresqlPackages.pg_rational: modernize

pkgs/servers/sql/postgresql/ext/pg_rational.nix

@@ -1,9 +1,8 @@
 {
-  stdenv,
+  buildPostgresqlExtension,
   fetchFromGitHub,
   lib,
   postgresql,
-  buildPostgresqlExtension,
 }:
 
 buildPostgresqlExtension rec {
@@ -13,15 +12,15 @@ buildPostgresqlExtension rec {
   src = fetchFromGitHub {
     owner = "begriffs";
     repo = "pg_rational";
-    rev = "v${version}";
-    sha256 = "sha256-Sp5wuX2nP3KGyWw7MFa11rI1CPIKIWBt8nvBSsASIEw=";
+    tag = "v${version}";
+    hash = "sha256-Sp5wuX2nP3KGyWw7MFa11rI1CPIKIWBt8nvBSsASIEw=";
   };
 
-  meta = with lib; {
+  meta = {
     description = "Precise fractional arithmetic for PostgreSQL";
     homepage = "https://github.com/begriffs/pg_rational";
-    maintainers = with maintainers; [ netcrns ];
+    maintainers = with lib.maintainers; [ netcrns ];
     platforms = postgresql.meta.platforms;
-    license = licenses.mit;
+    license = lib.licenses.mit;
   };
 }