Fix some test failures

- Set `_bot` on DiscordBot instances instead of its getter
- Add a missing await to prevent a potential test timeout

Signed-off-by: Andrew Ferrazzutti <andrewf@element.io>

test/test_discordbot.ts

@@ -115,7 +115,7 @@ describe("DiscordBot", () => {
                 mockBridge,
                 {},
             );
-            discord.bot = { user: { id: "654" } };
+            discord._bot = { user: { id: "654" } };
             discord.userSync = {
                 OnUpdateUser: async () => { },
             };

test/test_store.ts

@@ -26,7 +26,7 @@ describe("DiscordStore", () => {
     describe("init", () => {
         it("can create a db", async () => {
             const store = new DiscordStore(":memory:");
-            return store.init();
+            await store.init();
         });
     });
     describe("addUserToken", () => {