MNT Fix siteconfig behat test running on kitchen-sink

tests/behat/src/LoginContext.php

@@ -5,6 +5,7 @@
 use Page;
 use PHPUnit\Framework\Assert;
 use SilverStripe\BehatExtension\Context\LoginContext as BehatLoginContext;
+use SilverStripe\SiteConfig\SiteConfig;
 
 class LoginContext extends BehatLoginContext
 {
@@ -26,7 +27,11 @@ public function pagesShouldBeEditableBy($negative, $permCode)
         $password = 'Password!456';
         $member = $this->generateMemberWithPermission($email, $password, $permCode);
         $canEdit = strstr($negative ?? '', 'not') ? false : true;
-
+        // Flush the SiteConfig cache so that siteconfig behat tests that update the the
+        // SiteConfig DataObject will not be referring to stale version of themselves
+        // which happens because SiteConfig::current_site_config() uses DataList::get_one()
+        // which will cache by default
+        SiteConfig::current_site_config()->flushCache();
         if ($canEdit) {
             Assert::assertTrue($page->canEdit($member), 'The member can edit this page');
         } else {