Updated repo.targets to run only Nano functional tests when RUN_TESTS_ON_NANO is set to 'true'
Updated repo.targets to run only Nano functional tests when RUN_TESTS_ON_NANO is set to 'true'

aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore