Remove awaitAllRouteRenderers functionality

There's no reason to await the route renderers of our initial routes now
that suspense and preloading works properly.

router/RelayRouter.res

@@ -247,13 +247,7 @@ module Router = {
           }
         },
         postRouterEvent: postRouterEvent,
-      },
-      () => {
-        initialMatches
-        ->Belt.Array.map(({route}) => route.loadRouteRenderer())
-        ->Js.Promise.all
-        ->Js.Promise.then_(_ => Js.Promise.resolve(), _)
-      },
+      }
     )
   }
 }

router/RelayRouter.resi

@@ -18,7 +18,7 @@ module Router: {
     ~routes: array<Types.route>,
     ~routerEnvironment: RouterEnvironment.t,
     ~environment: RescriptRelay.Environment.t,
-  ) => (Types.cleanupFn, Types.routerContext, Types.awaitAllRouteRenderers)
+  ) => (Types.cleanupFn, Types.routerContext)
 }
 
 module Provider: {

router/RelayRouter__Types.res

@@ -55,7 +55,6 @@ type subFn = currentRouterEntry => unit
 type unsubFn = unit => unit
 type cleanupFn = unit => unit
 type callback = unit => unit
-type awaitAllRouteRenderers = unit => Js.Promise.t<unit>
 
 type routerEvent =
   | OnBeforeNavigation({currentLocation: RelayRouter__Bindings.History.location})

src/EntryClient.res

@@ -5,7 +5,7 @@ let boot = () => {
   Js.log("[debug] Doing boot")
 
   RelaySSRUtils.bootOnClient(~rootElementId="root", ~render=() => {
-    let (_, routerContext, _) = RelayRouter.Router.make(
+    let (_, routerContext) = RelayRouter.Router.make(
       ~routes,
       ~environment=RelayEnv.environment,
       ~routerEnvironment,

src/EntryServer.res

@@ -43,7 +43,7 @@ let default = (~request, ~response, ~clientScripts) => {
 
   let routes = RouteDeclarations.make()
 
-  let (cleanup, routerContext, _) = RelayRouter.Router.make(
+  let (cleanup, routerContext) = RelayRouter.Router.make(
     ~routes,
     ~environment,
     ~routerEnvironment,