style: deduplicate label rules in ship queue SCSS

Merge identical &__label and &__filters label blocks into a single
grouped selector, removing 7 duplicate lines.

Author: Nullskulls

app/assets/stylesheets/pages/certification/ships/_index.scss

@@ -65,7 +65,8 @@
     border-radius: 12px;
   }
 
-  &__label {
+  &__label,
+  &__filters label {
     display: block;
     font-size: 0.75rem;
     text-transform: uppercase;
@@ -306,15 +307,6 @@
     gap: var(--space-m);
     padding: var(--space-m) var(--space-l);
     margin-bottom: var(--space-l);
-
-    label {
-      display: block;
-      font-size: 0.75rem;
-      text-transform: uppercase;
-      letter-spacing: 0.06em;
-      color: var(--muted);
-      margin-bottom: var(--space-xxs);
-    }
   }
 
   &__filter {