debugging-sos-lldb-via-core: work around lldb deadlock.

[tmds]

This works around the deadlock on Fedora 43, RHEL 9 and RHEL 10.

Fixes #392

[tmds]

Alpine legs are failing with:

Unhandled exception: System.ComponentModel.Win32Exception (2): An error occurred trying to start process 'rpm' with working directory '/__w/dotnet-regular-tests/dotnet-regular-tests'. No such file or directory
   at System.Diagnostics.Process.ForkAndExecProcess(ProcessStartInfo startInfo, String resolvedFilename, String[] argv, String[] envp, String cwd, Boolean setCredentials, UInt32 userId, UInt32 groupId, UInt32[] groups, Int32& stdinFd, Int32& stdoutFd, Int32& stderrFd, Boolean usesTerminal, Boolean throwOnNoExec) in /_/src/runtime/artifacts/source-build/self/src/src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Unix.cs:line 498

[omajid]

Thanks!