.NET format has 7.0 references in the tooling going into 8.0.100

[marcpopMSFT]

See dotnet/sdk#34245

There are some packages being pulled in that target 7.0 and unless you have scenarios where format is loaded into the 7.0 runtime, it's recommended to reference the 8.0 versions. The issue is that we don't want you adding codeflow from runtime to increase complexity of the codeflow graph. With rc1 being go live, the recommendation would be to target RC1 release versions once it ships and the move to RC2 and then 8.0.0.