Fixed modal footer button styles when buttons and links are mixed

no issue

- when buttons and button-like links were mixed in a modal footer, the link did not inherit the expected button styles and if the link followed a button the two became smushed together because of missing left margins

ghost/admin/app/styles/components/modals-new.css

@@ -249,14 +249,13 @@
     justify-content: space-between;
 }
 
-.modal-footer button {
-    margin-left: 12px;
+.modal-footer .gh-btn {
     min-width: 100px;
     text-align: center;
 }
 
-.modal-footer button:first-of-type {
-    margin-left: 0;
+.modal-footer .gh-btn:not(:first-child) {
+    margin-left: 12px;
 }
 
 .modal-footer-hint {