Bug 1838939 - Part 5: Use design system typography in addons r=extension-reviewers,desktop-theme-reviewers,robwu,dao

Differential Revision: https://phabricator.services.mozilla.com/D186034

Author: Jules Simplicio

toolkit/mozapps/extensions/content/aboutaddons.css

@@ -192,8 +192,6 @@ message-bar-stack > * {
 /* List sections */
 
 .list-section-heading {
-  font-size: 17px;
-  font-weight: 600;
   margin-bottom: 16px;
 }
 
@@ -301,7 +299,7 @@ addon-card[expanded] .update-postponed-bar + .addon-card-message {
 
 .addon-name {
   font-size: 16px;
-  font-weight: 600;
+  font-weight: var(--font-weight-bold);
   line-height: 22px;
   margin: 0;
   margin-inline-end: 8px;
@@ -358,7 +356,7 @@ addon-card[expanded] .update-postponed-bar + .addon-card-message {
 
 .theme-enable-button {
   min-width: auto;
-  font-size: 13px;
+  font-size: var(--font-size-small);
   min-height: auto;
   height: 24px;
   margin: 0;