Azure Monitor: Externalise kusto (#84749)

fix(azuremonitor): externalise kusto so it loads via core

public/app/plugins/datasource/azuremonitor/webpack.config.ts

@@ -1,3 +1,14 @@
-import config from '@grafana/plugin-configs/webpack.config';
+import type { Configuration } from 'webpack';
+import { merge } from 'webpack-merge';
+
+import grafanaConfig from '@grafana/plugin-configs/webpack.config';
+
+const config = async (env: Record<string, unknown>): Promise<Configuration> => {
+  const baseConfig = await grafanaConfig(env);
+
+  return merge(baseConfig, {
+    externals: ['@kusto/monaco-kusto'],
+  });
+};
 
 export default config;