chore: remove deprecated keepConnectionAlive

Author: kamilmysliwiec

lib/interfaces/typeorm-options.interface.ts

@@ -24,11 +24,6 @@ export type TypeOrmModuleOptions = {
    * If `true`, entities will be loaded automatically.
    */
   autoLoadEntities?: boolean;
-  /**
-   * If `true`, connection will not be closed on application shutdown.
-   * @deprecated
-   */
-  keepConnectionAlive?: boolean;
   /**
    * If `true`, will show verbose error messages on each connection retry.
    */