Enable dynamic Actor loading by default

[jirispilka]

Since Claude Desktop supports it, let’s enable it by default. Hopefully, other clients will follow.

[jirispilka]

@MichalKalita to fix this, we will need to update it at several places 🙄

• github/apify/actors-mcp-server (code and ./actor/Actor.md) (this is the least important as we'll deprecate it). We are using it since this Actor is registered at all MCP registries ...
• github/apify/apify-mcp-server
• github/apify/apify-docs