Loki: Don't use _ numerical separator (#18016)

It breaks the build on a fresh checkout and install.

Fixes: #18015

public/app/plugins/datasource/loki/language_provider.ts

@@ -22,7 +22,7 @@ const DEFAULT_KEYS = ['job', 'namespace'];
 const EMPTY_SELECTOR = '{}';
 const HISTORY_ITEM_COUNT = 10;
 const HISTORY_COUNT_CUTOFF = 1000 * 60 * 60 * 24; // 24h
-const NS_IN_MS = 1_000_000;
+const NS_IN_MS = 1000000;
 export const LABEL_REFRESH_INTERVAL = 1000 * 30; // 30sec
 
 const wrapLabel = (label: string) => ({ label });