add missing bindThis to several onApplicationShutdown hooks

packages/backend/src/GlobalModule.ts

@@ -198,6 +198,7 @@ export class GlobalModule implements OnApplicationShutdown {
 		this.logger.info('Global module disposed.');
 	}
 
+	@bindThis
 	async onApplicationShutdown(signal: string): Promise<void> {
 		await this.dispose();
 	}

packages/backend/src/core/QueueModule.ts

@@ -157,6 +157,7 @@ export class QueueModule implements OnApplicationShutdown {
 		this.logger.info('Queue module disposed.');
 	}
 
+	@bindThis
 	async onApplicationShutdown(signal: string): Promise<void> {
 		await this.dispose();
 	}

packages/backend/src/core/activitypub/models/ApPersonService.ts

@@ -142,6 +142,7 @@ export class ApPersonService implements OnModuleInit, OnApplicationShutdown {
 		this.logger = this.apLoggerService.logger;
 	}
 
+	@bindThis
 	onApplicationShutdown(): void {
 		this.dispose();
 	}