chore: sync version with Fable 5.0.0-alpha.20 (#160)

Override release-please version to stay in sync with Fable versioning.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.5 <[email protected]>

Author: dbrattli

.release-please-manifest.json

@@ -1,3 +1,3 @@
 {
-  ".": "5.0.0-alpha.11"
+  ".": "5.0.0-alpha.20"
 }