Clarify description of new solver banned features

Co-authored-by: Tshepang Mbambo <hopsi@tuta.io>

Author: reddevilmidzy

src/feature-gate-ck.md

@@ -61,7 +61,7 @@ in `check_crate` and its AST visitor.
 - `check_incompatible_features`: Ensures incompatible feature combinations
   (declared in `rustc_feature::INCOMPATIBLE_FEATURES`) are not used together.
 - `check_new_solver_banned_features`: Bans features incompatible with
-  certain compiler modes (e.g., the next trait solver).
+  compiler mode for the next trait solver.
 - **Parser-gated spans**: Processes the `GatedSpans` recorded during parsing.
 
 ### AST Visitor