chore: release 1.1.0

Minor rather than major: adding a parent class widens what an existing
`except` catches, it does not break one. Callers already catching
GovernanceBackendError keep working untouched.

The wiki sync in the release checklist is a no-op this time. The doc site
was taken down entirely on 2026-08-02 for accuracy reasons, and its
remaining landing page points at CHANGELOG.md as the version source of
truth, which this commit updates.

src/polygateway/__init__.py

@@ -32,7 +32,7 @@ from polygateway.types import (
     SourceConfig,
 )
 
-__version__ = "1.0.6"
+__version__ = "1.1.0"
 
 __all__ = [
     "DEFAULT_PROFILES",