Pagesで変数削除するとそれ以外の変数が複製されるみたいなバグを修正

src/client/pages/page-editor/page-editor.vue

@@ -342,12 +342,7 @@ export default defineComponent({
 		},
 
 		removeVariable(v) {
-			const i = this.variables.findIndex(x => x.name === v.name);
-			const newValue = [
-				...this.variables.slice(0, i),
-				...this.variables.slice(i + 1)
-			];
-			this.variables = newValue;
+			this.variables = this.variables.filter(x => x.name !== v.name);
 		},
 
 		getPageBlockList() {