chore: minor auth related improvements (#4483)

* chore: show `(optional)` in label of non-required fields.

* chore: fix github auth button text color.

* chore: minor ui/ ux improvement in oauth options.

space/components/account/oauth/github-button.tsx

@@ -33,7 +33,7 @@ export const GithubOAuthButton: FC<GithubOAuthButtonProps> = (props) => {
         width={20}
         alt="GitHub Logo"
       />
-      <span className="text-onboarding-text-200">{text}</span>
+      {text}
     </button>
   );
 };