Add changelog for 0.50.0

CHANGELOG.md

+## 0.50.0 (2025-01-10)
+
+### Removed (1 change)
+
+- [Remove outdated OpenTofu versions to reduce build matrix](https://gitlab.com/components/opentofu/-/commit/78e65a570566747f6397b8b19381821309b0cc74) ([merge request](https://gitlab.com/components/opentofu/-/merge_requests/221))
+
 ## 0.49.0 (2025-01-06)
 
 No changes.