Disable node reuse in AzDO builds on persistent machines, add FreeBSD (dotnet/core-setup#4950)
* Disable node reuse in AzDO builds
Removes a source of cross-contamination on persistent build machines causing "Assembly with same name is already loaded" errors.
* Revert "Remove FreeBSD temporarily: official build fails"
This reverts commit dotnet/core-setup@
a8f4c17fef017f6a8c1a65aa73acf31e5d1ca173.
Commit migrated from https://github.com/dotnet/core-setup/commit/
4191cb60d17ed4ef30c0819a1bc5ec61de83d2cf