chore: release 2.2.1-beta.2 (#251)

Bumps past the published v2.2.1-beta.1 (which shipped the config-merge
regression, PR #250) — PyPI versions are immutable so the fix ships as a new
beta.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: rishigupta1599

percy/version.py

@@ -1 +1 @@
-__version__ = "2.2.1-beta.1"
+__version__ = "2.2.1-beta.2"