Fixes microsoft#204923 (microsoft#205605)

fix microsoft#204923

Author: benibenj

src/vs/workbench/browser/parts/editor/media/multieditortabscontrol.css

@@ -386,11 +386,13 @@
 .monaco-workbench .part.editor > .content .editor-group-container.active > .title .tabs-container > .tab.sticky.dirty > .tab-actions .action-label:not(:hover)::before,
 .monaco-workbench .part.editor > .content .editor-group-container > .title .tabs-container > .tab.sticky.dirty > .tab-actions .action-label:not(:hover)::before {
 	content: "\ebb2"; /* use `pinned-dirty` icon unicode for sticky-dirty indication */
+	font-family: 'codicon';
 }
 
 .monaco-workbench .part.editor > .content .editor-group-container.active > .title .tabs-container > .tab.dirty > .tab-actions .action-label:not(:hover)::before,
 .monaco-workbench .part.editor > .content .editor-group-container > .title .tabs-container > .tab.dirty > .tab-actions .action-label:not(:hover)::before {
 	content: "\ea71"; /* use `circle-filled` icon unicode for dirty indication */
+	font-family: 'codicon';
 }
 
 .monaco-workbench .part.editor > .content .editor-group-container > .title .tabs-container > .tab.active > .tab-actions .action-label,

src/vs/workbench/contrib/files/browser/views/media/openeditors.css

@@ -38,10 +38,12 @@
 
 .open-editors .monaco-list .monaco-list-row.dirty:not(:hover) > .monaco-action-bar .codicon-pinned::before {
 	content: "\ebb2"; /* use `pinned-dirty` icon unicode for sticky-dirty indication */
+	font-family: 'codicon';
 }
 
 .open-editors .monaco-list .monaco-list-row.dirty:not(:hover) > .monaco-action-bar .codicon-close::before {
 	content: "\ea71"; /* use `circle-filled` icon unicode for dirty indication */
+	font-family: 'codicon';
 }
 
 .open-editors .monaco-list .monaco-list-row > .monaco-action-bar .action-close-all-files,