vendor/fontstash: fix 'AddFont' proc group for JS target

vendor/fontstash/fontstash_other.odin

@@ -0,0 +1,10 @@
+//+build js
+package fontstash
+
+AddFontPath :: proc(
+	ctx: ^FontContext,
+	name: string,
+	path: string,
+) -> int {
+	panic("fontstash.AddFontPath is unsupported on the JS target")
+}