chore(arcade-mcp-server): promote 1.22.0rc1 to 1.22.0 (#848)

## Summary

- Removes the `rc1` pre-release suffix from `arcade-mcp-server` version,
promoting it to the stable `1.22.0` release.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: this is a metadata-only version bump with no runtime or
dependency changes.
> 
> **Overview**
> Promotes `arcade-mcp-server` to the stable `1.22.0` release by
removing the `rc1` suffix in `libs/arcade-mcp-server/pyproject.toml`.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
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code reviews on this repo. Configure
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Author: EricGustin

libs/arcade-mcp-server/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "arcade-mcp-server"
-version = "1.22.0rc1"
+version = "1.22.0"
 description = "Model Context Protocol (MCP) server framework for Arcade.dev"
 readme = "README.md"
 authors = [{ name = "Arcade.dev" }]