[cppyy] Skip crashing test using boost::type_erasure

It was enabled in commit 50ae29d and marked as xfail(strict=True)
in commit a7131ff, but is still crashing with assertions enabled
on AlmaLinux 8: "Must not nest within unloading transaction"

Author: hahnjo

bindings/pyroot/cppyy/cppyy/test/test_boost.py

@@ -141,7 +141,7 @@ def setup_class(cls):
         cppyy.include("boost/type_erasure/member.hpp")
         cppyy.include("boost/mpl/vector.hpp")
 
-    @mark.xfail(strict=True, reason="TClassInfo for 'Lengths' is missing")
+    @mark.xfail(run=False, reason="TClassInfo for 'Lengths' is missing & triggering Cling assertions during unloading")
     def test01_erasure_usage(self):
         """boost::type_erasure usage"""