changelog: use removed instead of deprecated

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: querolita

CHANGELOG.md

@@ -20,7 +20,7 @@ and this project adheres to
 - Fix lookup selector polynomials to work correctly when chunking is in place
   ([#3541](https://github.com/o1-labs/proof-systems/pull/3541))
 
-#### Deprecated
+### Removed
 
 - Fully remove Cairo gate variants in `GateType`
   ([#3543](https://github.com/o1-labs/proof-systems/pull/3543))