chore: bump version to 0.6.0 for surface-telemetry release

The new `surface` / `surface_version` / `surface_metadata` constructor
kwargs are an additive feature; downstream wrappers (e.g. devhelm-mcp-server)
need to pin `devhelm>=0.6.0` to use them, so cutting a minor bump.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: caballeto

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "devhelm"
-version = "0.5.0"
+version = "0.6.0"
 description = "DevHelm SDK for Python — typed client for monitors, incidents, alerting, and more"
 authors = [{ name = "DevHelm", email = "hello@devhelm.io" }]
 license = "MIT"