Move required styles for add issueable form

The styling for the add linked issue form is missing for core.

This is related to https://gitlab.com/gitlab-org/gitlab/-/issues/212329
and fixes https://gitlab.com/gitlab-org/gitlab/-/issues/273558
and https://gitlab.com/gitlab-org/gitlab/-/issues/258678.

app/assets/stylesheets/pages/issuable.scss

@@ -792,6 +792,40 @@
   }
 }
 
+.add-issuable-form-input-token-list {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: baseline;
+  list-style: none;
+  margin-bottom: 0;
+  padding-left: 0;
+}
+
+.add-issuable-form-token-list-item {
+  max-width: 100%;
+  margin-bottom: $gl-vert-padding;
+  margin-right: 5px;
+}
+
+.add-issuable-form-input-list-item {
+  flex: 1;
+  min-width: 200px;
+  margin-bottom: $gl-vert-padding;
+}
+
+.add-issuable-form-input {
+  width: 100%;
+  border: 0;
+
+  &:focus {
+    outline: none;
+  }
+}
+
+.add-issuable-form-actions {
+  margin-top: $gl-padding;
+}
+
 .time-tracker {
   .sidebar-collapsed-icon {
     > .stopwatch-svg {

changelogs/unreleased/258678-move-add-issuable-styles-to-core.yml

+---
+title: Fix style for adding a related issue in free tiers
+merge_request: 58893
+author: Michael Telgkamp @michael.telgkamp
+type: fixed

ee/app/assets/stylesheets/pages/issuable.scss

@@ -46,40 +46,6 @@
   }
 }
 
-.add-issuable-form-input-token-list {
-  display: flex;
-  flex-wrap: wrap;
-  align-items: baseline;
-  list-style: none;
-  margin-bottom: 0;
-  padding-left: 0;
-}
-
-.add-issuable-form-token-list-item {
-  max-width: 100%;
-  margin-bottom: $gl-vert-padding;
-  margin-right: 5px;
-}
-
-.add-issuable-form-input-list-item {
-  flex: 1;
-  min-width: 200px;
-  margin-bottom: $gl-vert-padding;
-}
-
-.add-issuable-form-input {
-  width: 100%;
-  border: 0;
-
-  &:focus {
-    outline: none;
-  }
-}
-
-.add-issuable-form-actions {
-  margin-top: $gl-padding;
-}
-
 .limit-container-width {
   .epic-page-container .issuable-details,
   .emoji-list-container {