fix: axios header 추가

src/libs/axios.ts

@@ -1,12 +1,13 @@
 import { useSpinnerStore } from '@/store/spinnerStore'
 import axios from 'axios'
 
-export const axiosInstance = (url: string | null | undefined) => {
+export const axiosInstance = (url: string | null | undefined, headers?: Record<string, string>) => {
   const baseURL = url || process.env.NEXT_PUBLIC_API_URL
   const instance = axios.create({
     baseURL,
     headers: {
       Accept: 'application/json',
+      ...headers,
     },
   })