haskell.compiler.ghc946: remove left-over patch

This was specific to GHC 9.4.6 and should have been dropped in
95c179f9fb as well.

pkgs/development/compilers/ghc/9.4.6-bytestring-posix-source.patch

@@ -1,15 +0,0 @@
-Make sure that the appropriate feature flags are set when
-Rts.h is included, so that clockid_t is defined.
-
-diff --git a/cbits/is-valid-utf8.c b/cbits/is-valid-utf8.c
-index 01b3b41..c69596a 100644
---- a/libraries/bytestring/cbits/is-valid-utf8.c
-+++ b/libraries/bytestring/cbits/is-valid-utf8.c
-@@ -29,6 +29,7 @@ SUCH DAMAGE.
- */
- #pragma GCC push_options
- #pragma GCC optimize("-O2")
-+#include "rts/PosixSource.h"
- #include <stdbool.h>
- #include <stddef.h>
- #include <stdint.h>

pkgs/development/compilers/ghc/common-make-native-bignum.nix

@@ -410,12 +410,6 @@ stdenv.mkDerivation (
       })
     ]
 
-    ++ lib.optionals (version == "9.4.6") [
-      # Work around a type not being defined when including Rts.h in bytestring's cbits
-      # due to missing feature macros. See https://gitlab.haskell.org/ghc/ghc/-/issues/23810.
-      ./9.4.6-bytestring-posix-source.patch
-    ]
-
     ++ lib.optionals (stdenv.targetPlatform.isDarwin && stdenv.targetPlatform.isAarch64) [
       # Prevent the paths module from emitting symbols that we don't use
       # when building with separate outputs.