Use monospace font for overloads

From #84682

This prevents slight shifting of the parameter hints box while going through the overloads

src/vs/editor/contrib/parameterHints/parameterHints.css

@@ -95,6 +95,7 @@
 	height: 12px;
 	line-height: 12px;
 	opacity: 0.5;
+	font-family: var(--monaco-monospace-font);
 }
 
 .monaco-editor .parameter-hints-widget .signature .parameter.active {