Disable concurreny for dotnet samples
Disable concurreny for dotnet samples

All samples in the same directory will use the same bin obj directory
and dotnet/cli doesn't support concurrency on few of them.
e.g. obj/project.assets.json

google/or-tools,google/or-tools,google/or-tools,or-tools/or-tools,or-tools/or-tools,or-tools/or-tools,or-tools/or-tools,google/or-tools,google/or-tools,or-tools/or-tools,google/or-tools,or-tools/or-tools