feat(tvix/nar-bridge): increase timeouts

In some cases, Nix is not able to stream the NAR file fast enough. Bump the
timeouts for now. We might want to get a better understanding in what's
happening here long-term, and/or make the timeouts configurable.

Change-Id: Ieaa9c8f04bc73c6ce0679a058d07eaf87126634e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9340
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

tvix/nar-bridge/pkg/server/server.go

@@ -77,9 +77,9 @@ func (s *Server) ListenAndServe(addr string) error {
 	srv := &http.Server{
 		Addr:         addr,
 		Handler:      s.handler,
-		ReadTimeout:  50 * time.Second,
-		WriteTimeout: 100 * time.Second,
-		IdleTimeout:  150 * time.Second,
+		ReadTimeout:  500 * time.Second,
+		WriteTimeout: 500 * time.Second,
+		IdleTimeout:  500 * time.Second,
 	}
 
 	return srv.ListenAndServe()