gcc11: drop libgcc-aarch64-darwin-detection upstreamed patch

Randy notes that it was already upstream in latest patches and is not
needed anymore:

- 8eef9a10b4/libgcc/config.host (L229-L231)
- https://github.com/iains/gcc-11-branch/blob/gcc-11-5-darwin/libgcc/config/t-darwin-rpath

pkgs/development/compilers/gcc/patches/11/libgcc-aarch64-darwin-detection.patch

@@ -1,21 +0,0 @@
-diff -u a/libgcc/config.host b/libgcc/config.host
---- a/libgcc/config.host	2023-11-05 11:01:55.778638446 -0500
-+++ b/libgcc/config.host	2023-11-05 11:07:29.405103979 -0500
-@@ -227,7 +227,7 @@
-   tmake_file="$tmake_file t-slibgcc-darwin"
-   # newer toolsets produce warnings when building for unsupported versions.
-   case ${host} in
--    *-*-darwin1[89]* | *-*-darwin2* )
-+    *-*-darwin1[89]* | *-*-darwin2* | aarch64*-*-darwin*)
-       tmake_file="t-darwin-min-8 $tmake_file"
-       ;;
-     *-*-darwin9* | *-*-darwin1[0-7]*)
-diff -ur a/libgcc/config/t-darwin-rpath b/libgcc/config/t-darwin-rpath
---- a/libgcc/config/t-darwin-rpath	2023-11-05 11:34:18.691150009 -0500
-+++ b/libgcc/config/t-darwin-rpath	2023-11-05 11:50:36.968920904 -0500
-@@ -2,4 +2,4 @@
- SHLIB_RPATH = @rpath
-
- # Which does not work for Darwin < 9
--HOST_LIBGCC2_CFLAGS += -mmacosx-version-min=10.5
-+SHLIB_LOADER_PATH = -Wl,-rpath,@loader_path

pkgs/development/compilers/gcc/patches/default.nix

@@ -201,9 +201,6 @@ in
 
 ## gcc 11.0 and older ##############################################################################
 
-# libgcc’s `configure` script misdetects aarch64-darwin, resulting in an invalid deployment target.
-++ optional (is11 && stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64) ./11/libgcc-aarch64-darwin-detection.patch
-
 # openjdk build fails without this on -march=opteron; is upstream in gcc12
 ++ optionals (is11) [ ./11/gcc-issue-103910.patch ]