purescript.tests.minimal-module: use lib.sources.sourceByGlobs

Filter src to the .purs and .js files actually compiled, dropping
default.nix from the closure.

pkgs/development/compilers/purescript/purescript/test-minimal-module/default.nix

@@ -1,11 +1,17 @@
 {
+  lib,
   runCommand,
   purescript,
   nodejs,
 }:
 
 runCommand "purescript-test-minimal-module" { } ''
-  ${purescript}/bin/purs compile -o ./output ${./.}/Main.purs
+  ${purescript}/bin/purs compile -o ./output ${
+    lib.sources.sourceByGlobs ./. [
+      "*.purs"
+      "*.js"
+    ]
+  }/Main.purs
 
   echo 'import {main} from "./output/Main/index.js"; main()' > node.mjs