Refactor file type insertion method in machine service

Replaced variable assignment with direct return of the database insertion result to streamline the code. This improves readability and eliminates an unnecessary variable.

apps/backend/src/app/machines/machines.service.ts

@@ -149,7 +149,7 @@ export class MachinesService {
 		if (fileType.length !== 1)
 			throw new NotFoundException("File type not found.");
 
-		const insertFileType = await this.database
+		return await this.database
 			.use()
 			.insert(FilesTypeForMachine)
 			.values({
@@ -158,7 +158,6 @@ export class MachinesService {
 			})
 			.prepare("insertFileTypeForMachine")
 			.execute();
-		return insertFileType;
 	}
 
 	async getFilesTypes(machineId: string) {