Clean up CSS for status-box in issuables for performance

Changelog: changed
Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

app/assets/stylesheets/framework/issue_box.scss

@@ -5,16 +5,7 @@
  */
 
 .status-box {
-
-  /* Extra small devices (phones, less than 768px) */
-  /* No media query since this is the default in Bootstrap */
-  padding: 5px 11px;
-  margin-top: 4px;
-  /* Small devices (tablets, 768px and up) */
-  @include media-breakpoint-up(sm) {
-    padding: 0 $gl-btn-padding;
-    margin-top: 5px;
-  }
+  padding: 0 $gl-btn-padding;
 
   border-radius: $border-radius-default;
   display: block;

app/assets/stylesheets/page_bundles/milestone.scss

@@ -38,18 +38,6 @@ $status-box-line-height: 26px;
         color: var(--blue-600, $blue-600);
       }
     }
-
-    .status-box {
-      font-size: $tooltip-font-size;
-      margin-top: 0;
-      margin-right: $gl-padding-4;
-      line-height: $status-box-line-height;
-
-      @include media-breakpoint-down(xs) {
-        line-height: unset;
-        padding: $gl-padding-4 $gl-input-padding;
-      }
-    }
   }
 }
 
@@ -199,11 +187,6 @@ $status-box-line-height: 26px;
   align-items: center;
   flex-wrap: wrap;
 
-  .status-box {
-    margin-top: 0;
-    order: 1;
-  }
-
   .milestone-buttons {
     margin-left: auto;
     order: 2;