feat: Remove Skeleton mixins

UNRELEASED-v9.md

@@ -42,6 +42,8 @@ Use [the changelog guidelines](/documentation/Versioning%20and%20changelog.md) t
 - Removed the `unstyled-list()` mixin and replaced any instances with values ([#4960](https://github.com/Shopify/polaris-react/pull/4960))
 - Removed `high-contrast-outline()` and `high-contrast-border()` mixins and replaced any instances with tokens and values ([#4962](https://github.com/Shopify/polaris-react/pull/4962))
 - Removed the `map-extend` scss function ([#4970](https://github.com/Shopify/polaris-react/pull/4970))
+- Removed the `skeleton-page-header-layout` scss mixin ([#4991](https://github.com/Shopify/polaris-react/pull/4991))
+- Removed the `skeleton-page-secondary-actions-layout` scss mixin ([#4991](https://github.com/Shopify/polaris-react/pull/4991))
 - Updated `--p-icon-size` custom property to `--p-icon-size-small` ([#4990](https://github.com/Shopify/polaris-react/pull/4990))
 - Replaced `icon-size()` SCSS function with the `--p-icon-size-medium` custom property ([#4990](https://github.com/Shopify/polaris-react/pull/4990))
 - Removed the `state()` scss mixin ([#4989](https://github.com/Shopify/polaris-react/pull/4989))

src/components/SkeletonPage/SkeletonPage.scss

@@ -22,7 +22,7 @@ $skeleton-display-text-max-width: 120px;
 
 .Header {
   @include page-header-layout;
-  @include skeleton-page-header-layout;
+  padding-bottom: var(--p-space-2);
 }
 
 .BreadcrumbAction {
@@ -88,7 +88,11 @@ $skeleton-display-text-max-width: 120px;
 }
 
 .Actions {
-  @include skeleton-page-secondary-actions-layout;
+  margin-top: var(--p-space-2);
+  display: flex;
+  flex-direction: row-reverse;
+  justify-content: flex-end;
+  align-items: center;
 }
 
 .Action {

src/styles/shared/_skeleton.scss

@@ -32,15 +32,3 @@ $thumbnail-sizes: (
     }
   }
 }
-
-@mixin skeleton-page-secondary-actions-layout {
-  margin-top: var(--p-space-2);
-  display: flex;
-  flex-direction: row-reverse;
-  justify-content: flex-end;
-  align-items: center;
-}
-
-@mixin skeleton-page-header-layout {
-  padding-bottom: var(--p-space-2);
-}