Revert to previous scss and instead use gl class

Issue: https://gitlab.com/gitlab-org/gitlab/-/issues/297484

app/assets/stylesheets/framework/highlight.scss

@@ -45,8 +45,7 @@
 
     a {
       font-family: $monospace-font;
-      display: flex;
-      justify-content: flex-end;
+      display: block;
       font-size: $code-font-size !important;
       white-space: nowrap;
 

app/views/projects/blame/show.html.haml

@@ -47,7 +47,7 @@
 
             %td.line-numbers
               - (current_line...(current_line + line_count)).each do |i|
-                %a.diff-line-num{ href: "#L#{i}", id: "L#{i}", 'data-line-number' => i }
+                %a.diff-line-num.gl-justify-content-end{ href: "#L#{i}", id: "L#{i}", 'data-line-number' => i, class: "gl-display-flex!" }
                   = link_icon
                   = i
                 \