Add UTC in the serverTimezone dropdown

src/components/settings/General.vue

@@ -26,6 +26,7 @@
                     {{ $t("Server Timezone") }}
                 </label>
                 <select id="timezone" v-model="settings.serverTimezone" class="form-select">
+                    <option value="UTC">UTC</option>
                     <option
                         v-for="(timezone, index) in timezoneList"
                         :key="index"

src/util.ts

@@ -9,7 +9,6 @@
 import * as dayjs  from "dayjs";
 import * as timezone from "dayjs/plugin/timezone";
 import * as utc from "dayjs/plugin/utc";
-import {R} from "redbean-node";
 
 export const isDev = process.env.NODE_ENV === "development";
 export const appName = "Uptime Kuma";