Block out the svm_diamondshape tests on Mono with dotnet#80350

Based on offline discussion with Vlad Brezae I have temporarily
disabled the svm_diamondshape test on Mono where it is causing
crashes in VTable construction that might take a bit to fix.

Thanks

Tomas

src/tests/issues.targets

@@ -1525,6 +1525,9 @@
         <ExcludeList Include="$(XunitTestBinBase)/Loader/classloader/MethodImpl/CovariantReturns/UnitTest/CompatibleWithTest/**">
             <Issue>Doesn't pass after LLVM AOT compilation.</Issue>
         </ExcludeList>
+        <ExcludeList Include="$(XunitTestBinBase)/Loader/classloader/StaticVirtualMethods/DiamondShape/**">
+            <Issue>https://github.com/dotnet/runtime/issues/80350</Issue>
+        </ExcludeList>
         <ExcludeList Include="$(XunitTestBinBase)/Loader/classloader/StaticVirtualMethods/InterfaceVariance/**">
             <Issue>Static virtual methods are not yet implemented in the Mono runtime.</Issue>
         </ExcludeList>