controller should be marked nullable

While 'SvelteComponent | null' seems to make it into the .tsx file
created by svelte2tsx, the subsequent tsc call seems to discard the
'| null' part when creating the .d.ts file. Hack around it with a cast
for now; this may be fixed if we move to ts_project in the future.

ts/graphs/GraphsPage.svelte

@@ -13,7 +13,7 @@
 
     export let search: string;
     export let days: number;
-    export let controller: SvelteComponent;
+    export let controller: SvelteComponent | null;
 
     let active = false;
     let sourceData: pb.BackendProto.GraphsOut | null = null;

ts/graphs/bootstrap.ts

@@ -1,6 +1,10 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
+/* eslint
+@typescript-eslint/no-explicit-any: "off",
+*/
+
 import type { SvelteComponent } from "svelte/internal";
 
 import { setupI18n } from "anki/i18n";
@@ -24,7 +28,7 @@ export { RevlogRange } from "./graph-helpers";
 export function graphs(
     target: HTMLDivElement,
     graphs: SvelteComponent[],
-    { search = "deck:current", days = 365, controller = null } = {}
+    { search = "deck:current", days = 365, controller = null as any } = {}
 ): void {
     const nightMode = checkNightMode();