refactor: replace deprecated String.prototype.substr() (#2187)

packages/hoppscotch-app/components/profile/Picture.vue

@@ -74,7 +74,7 @@ export default defineComponent({
       let color = "#"
       for (let i = 0; i < 3; i++) {
         const value = (hash >> (i * 8)) & 255
-        color += `00${value.toString(16)}`.substr(-2)
+        color += `00${value.toString(16)}`.slice(-2)
       }
       return color
     },

packages/hoppscotch-app/helpers/oauth.js

@@ -88,7 +88,7 @@ const getTokenConfiguration = async (endpoint) => {
 const generateRandomString = () => {
   const array = new Uint32Array(28)
   window.crypto.getRandomValues(array)
-  return Array.from(array, (dec) => `0${dec.toString(16)}`.substr(-2)).join("")
+  return Array.from(array, (dec) => `0${dec.toString(16)}`.slice(-2)).join("")
 }
 
 /**