refact: Simplify insertFile

Author: bastianallgeier

panel/src/components/Forms/Input/TextareaInput.vue

@@ -198,15 +198,9 @@ export default {
 			return input.value;
 		},
 		async insertFile(files) {
-			let value = null;
-
 			if (files?.length > 0) {
-				value = await this.insert(
-					files.map((file) => file.dragText).join("\n\n")
-				);
+				await this.insert(files.map((file) => file.dragText).join("\n\n"));
 			}
-
-			return value;
 		},
 		async insertUpload(files) {
 			await this.insertFile(files);