SDK 6.0.113 build freezes under source build

[kaniini]

Describe the bug

When doing a non-portable build, the "sdk in tarball" msbuild task fails to complete, getting stuck on "39>CoreResGen" step. All processes that stick around are contending on futexes, which indicates a deadlock of some kind.

To Reproduce

Run this build recipe with Melange, e.g. melange build dotnet6.yaml --arch x86_64.

Further technical details

The build uses .NET SDK 6.0.111 to bootstrap, as that is what Arcade downloads. Not sure if that could have anything to do with anything.

[kaniini]

No idea if it would be helpful but https://distfiles.dereferenced.org/build.log.txt is a build log.

[agocke]

@marcpopMSFT

[marcpopMSFT]

CC @dotnet/source-build-internal