Update src/doc/rustc/src/check-cfg.md

Co-authored-by: Urgau <[email protected]>

Author: tgross35

src/doc/rustc/src/check-cfg.md

@@ -126,10 +126,6 @@ As of `2025-01-02T`, the list of known names is as follows:
  - `target_has_atomic`
  - `target_has_atomic_equal_alignment`
  - `target_has_atomic_load_store`
- - `target_has_reliable_f16`
- - `target_has_reliable_f16_math`
- - `target_has_reliable_f128`
- - `target_has_reliable_f128_math`
  - `target_os`
  - `target_pointer_width`
  - `target_thread_local`