refactor: update color-mode usage to new composable

packages/hoppscotch-app/components/app/GitHubStarButton.vue

@@ -4,8 +4,8 @@
       title="Star Hoppscotch"
       href="https://github.com/hoppscotch/hoppscotch"
       :data-color-scheme="
-        $colorMode.value != 'light'
-          ? $colorMode.value == 'black'
+        colorMode.value != 'light'
+          ? colorMode.value == 'black'
             ? 'dark'
             : 'dark_dimmed'
           : 'light'
@@ -20,6 +20,9 @@
 
 <script setup lang="ts">
 import GithubButton from "vue-github-button"
+import { useColorMode } from "~/helpers/utils/composables"
+
+const colorMode = useColorMode()
 
 defineProps({
   size: {