Disable failing runtime test

```
/Users/runner/work/1/s/src/tests/JIT/jit64/opt/rngchk/RngchkStress2.cs(527,796): error CS8078: An expression is too long or complex to compile [/Users/runner/work/1/s/src/tests/JIT/jit64/opt/rngchk/RngchkStress2_o.csproj] [/Users/runner/work/1/s/src/tests/build.proj]
```
Issue: #87879

Author: radical

src/tests/JIT/jit64/jit64_3.csproj

@@ -1,7 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <ItemGroup>
     <MergedWrapperProjectReference Include="opt/**/*.??proj" />
+    <!-- Issue: https://github.com/dotnet/runtime/issues/87879 -->
+    <MergedWrapperProjectReference Remove="opt/rngchk/RngchkStress2*.??proj" />
   </ItemGroup>
 
   <Import Project="$(TestSourceDir)MergedTestRunner.targets" />
-</Project>
+</Project>