refactor: remove unnecessary as any cast in pkgsDiff

The `{} as any` initial value for `reduce(mergeRight, ...)` was
unnecessary — TypeScript can infer the initial value type from context
since the outer expression is already cast to
`Rx.Observable<logs.PackageManifestLog>`.

cli/default-reporter/src/reporterForClient/pkgsDiff.ts

@@ -115,7 +115,7 @@ export function getPkgsDiff (
   )
     .pipe(
       take(2),
-      reduce(mergeRight, {} as any) // eslint-disable-line @typescript-eslint/no-explicit-any
+      reduce(mergeRight, {})
     ) as Rx.Observable<logs.PackageManifestLog>
 
   return Rx.combineLatest(