fix[frontend](alerts): removed unused index-* pattern definition from alerts

Author: AlexSanchez-bit

frontend/src/app/shared/constants/main-index-pattern.constant.ts

@@ -1,7 +1,6 @@
 /**
  * Main index to use
  */
-export const MAIN_INDEX_PATTERN = 'index-*';
 export const ALERT_INDEX_PATTERN = 'v11-alert-*';
 export const LOG_INDEX_PATTERN = 'v11-log-*';
 export const LOG_INDEX_WINLOGBEAT = 'v11-log-wineventlog-*';