Build new nix {module,package,flake}. Adapt to new config variables

Co-authored-by: h7x4 <h7x4@nani.wtf>

dist/simplesamlphp-authsources.php

@@ -0,0 +1,9 @@
+<?php
+$config = array(
+
+    /* This is the name of this authentication source, and will be used to access it later. */
+    'default-sp' => array(
+        'saml:SP',
+        'idp' => 'https://idp.pvv.ntnu.no/',
+    ),
+);