Adds support for dependencies in scrapers in config

[rithviknishad]

When multiple scrapers are configured, there maybe situations where one scraper maybe dependent on another one.

We should be able to specify scraper dependencies similar to how it's there in docker's compose file.

[Akshat-0001]

I walked through the plugin runner locally to understand how scrapers are orchestrated. Plugins are loaded nd executed sequentially in runPlugins() based on the insertion order of config.leaderboard.plugins and the same order is reused for both setup and scrape phases. There is currently no way to explicitly declare dependencies so ordering is implicit and can break when one scraper assumes data from another.

It seems dependency support could fit cleanly at the config level (plugin IDs as keys) with validation and a topo-sorted execution order applied before loading/setup/scrape. Happy to try a small PR in this direction if that aligns with expectations.