fix: overlayBackgroundAlpha for chonk (#88785)

also, remove it from the theme, because it's only used in one place

Author: TkDodo

static/app/utils/theme/theme.chonk.tsx

@@ -825,11 +825,6 @@ const generateAliases = (
    */
   progressBackground: colors.gray100,
 
-  /**
-   * Overlay for partial opacity
-   */
-  overlayBackgroundAlpha: colors.gray100,
-
   /**
    * Tag progress bars
    */

static/app/utils/theme/theme.tsx

@@ -394,11 +394,6 @@ export const generateThemeAliases = (colors: Colors) => ({
    */
   progressBackground: colors.gray100,
 
-  /**
-   * Overlay for partial opacity
-   */
-  overlayBackgroundAlpha: color(colors.surface200).alpha(0.7).string(),
-
   /**
    * Tag progress bars
    */

static/app/views/dashboards/widgetCard/toolbar.tsx

@@ -1,4 +1,5 @@
 import styled from '@emotion/styled';
+import color from 'color';
 
 import {Button} from 'sentry/components/core/button';
 import {IconCopy, IconDelete, IconEdit, IconGrabbable} from 'sentry/icons';
@@ -74,7 +75,7 @@ const ToolbarPanel = styled('div')`
   justify-content: flex-end;
   align-items: flex-start;
 
-  background-color: ${p => p.theme.overlayBackgroundAlpha};
+  background-color: ${p => color(p.theme.surface300).alpha(0.7).string()};
   border-radius: calc(${p => p.theme.borderRadius} - 1px);
 `;