Don't involve pure modifier keys when resolving if in-chord (#139254)

Fixes #139152

Author: Jackson Kearl

src/vs/platform/list/browser/listService.ts

@@ -800,6 +800,10 @@ function createKeyboardNavigationEventFilter(container: HTMLElement, keybindingS
 	let inChord = false;
 
 	return event => {
+		if (event.toKeybinding().isModifierKey()) {
+			return false;
+		}
+
 		if (inChord) {
 			inChord = false;
 			return false;