Fix flaky admin users system spec (#4875)

Author: coalest

spec/system/admin/users_system_spec.rb

@@ -47,10 +47,7 @@
       expect(page).to have_content('User 123')
       select "Partner", from: "resource_type"
       find("div.input-group:has(.select2-container)").click
-      find('.select2-search__field', wait: 5).set("Partner ABC")
-      find(:xpath,
-        "//li[contains(@class, 'select2-results__option') and contains(., 'Partner ABC')]",
-        wait: 5).click
+      find("li.select2-results__option", text: "Partner ABC").click
       click_on 'Add Role'
 
       expect(page.find('.alert')).to have_content('Role added')