overlay coreos/user-patches: Drop esysroot patch for sys-devel/gcc

The updated version of gcc uses a Gentoo patch set that already
contains the removed patch.

sdk_container/src/third_party/coreos-overlay/coreos/user-patches/sys-devel/gcc/README.md

@@ -1,2 +0,0 @@
-The ESYSROOT patch can be dropped when updating sys-devel/gcc to at
-least 14.2.1_p20240817-r1.

sdk_container/src/third_party/coreos-overlay/coreos/user-patches/sys-devel/gcc/gcc-esysroot.patch

@@ -1,20 +0,0 @@
-diff -Naur a/gcc/gcc.cc b/gcc/gcc.cc
---- a/gcc/gcc.cc	2024-08-01 23:34:33.525082176 +0100
-+++ b/gcc/gcc.cc	2024-08-01 23:43:31.557156041 +0100
-@@ -5527,6 +5527,16 @@
- 	      "BINUTILS", PREFIX_PRIORITY_LAST, 0, 1);
-   free (tooldir_prefix);
-
-+  if (*cross_compile == '1' && !target_system_root_changed)
-+    {
-+      const char *esysroot = env.get("ESYSROOT");
-+      if (esysroot && esysroot[0] != '\0' && strcmp(esysroot, "/") != 0 && (!target_system_root || strcmp(esysroot, target_system_root) != 0))
-+	{
-+	  target_system_root = esysroot;
-+	  target_system_root_changed = 1;
-+	}
-+    }
-+
- #if defined(TARGET_SYSTEM_ROOT_RELOCATABLE) && !defined(VMS)
-   /* If the normal TARGET_SYSTEM_ROOT is inside of $exec_prefix,
-      then consider it to relocate with the rest of the GCC installation