Perf degradation in .NET 7 SDK preview 5

[vlada-shubina]

After move to dotnet SDK preview 5, the templating E2E tests became considerably slower.
We noticed the considerable slow down for dotnet restore and dotnet build.
The tests below are done exactly on the same environment, the only difference is SDK installed.
The time is average of 10 runs.

dotnet 7.0.100-preview.4.22178.9

	dotnet restore process	dotnet build process
Linux	1.097844967	2.0284816
Windows	1.24554	2.350077467
macOS 10.15	1.271835	2.4018087
macOS 11	1.4974926	2.8483784
macOS 12	1.3800725	2.6093628

dotnet 7.0.100-preview.5.22307.18

	dotnet restore process	dotnet build process
Linux	1.2233042	2.0828921
Windows	1.317997767	2.416077367
macOS 10.15	1.48888	2.6458135
macOS 11	1.863845	3.3911843
macOS 12	1.875765	3.345523

More details in: dotnet/templating#4942