Benchmark launcher fails in Google Colab when `slack_sdk` is not installed

[R-Palazzo]

Environment Details

• SDGym version: v0.14.3

Error Description

When trying to use the benchmark launcher in Google Colab, importing the launcher config fails because slack_sdk is not installed.

The launcher should be usable without Slack installed, since Slack is only needed for benchmark notification utilities.

Steps to reproduce

In Google Colab runtime:

from sdgym._benchmark_launcher.benchmark_config import BenchmarkConfig