Do not build a supposed-to-crash test which may or may not even compile
correctly any longer.

Bug: https://bugs.gentoo.org/955831

--- boost_1_88_0/libs/system/test/Jamfile.v2~	2025-04-03 13:37:30.000000000 +0200
+++ boost_1_88_0/libs/system/test/Jamfile.v2	2025-05-11 14:28:16.187753266 +0200
@@ -68,7 +68,7 @@ system-run before_main_test.cpp ;
 
 run-fail throws_assign_fail.cpp : : :
     # GCC 12 catches this at compile time with a warning
-    <toolset>gcc,<variant>release:<build>no ;
+    <toolset>gcc:<build>no ;
 
 system-run constexpr_test.cpp ;
 system-run win32_hresult_test.cpp ;