Release v3.50.3 (#11638)

chore: add changeset for v3.50.3

Co-authored-by: Roo Code <roomote@roocode.com>

Author: roomote-v0[bot]

.changeset/v3.50.3.md

@@ -0,0 +1,6 @@
+---
+"roo-cline": patch
+---
+
+- Fix: Correct Vertex AI claude-sonnet-4-6 model ID (#11625 by @yuvarajl, PR #11626 by @roomote)
+- Restore Unbound as a provider (PR #11624 by @pugazhendhi-m)