Mark /api/events endpoint as uncachable

The content of the events stream is generated live in response to
changes done in the system as they occur.  It therefore can't be
meaningfully cached or stored in any way.  Mark the response as
uncacheable to prevent potential problems with caches.

server/api/events.ts

@@ -43,6 +43,7 @@ export default defineEventHandler(async (event) => {
 	// Workaround to properly handle stream errors. See https://github.com/unjs/h3/issues/986
 	setHeader(event, "Access-Control-Allow-Origin", "*");
 	setHeader(event, "Content-Type", "text/event-stream");
+	setHeader(event, "Cache-Control", "no-store");
 	pipeline(stream as unknown as NodeJS.ReadableStream, event.node.res, (err) => { /* ignore */ });
 	event._handled = true;
 });