Upgrading roslyn bits causing version downgrades, needs further investigation

[maryamariyan]

Currently upgrading roslyn bits for dotnet/razor is a manual process and it used to be a straightforward upgrade as seen in #8443. In contrast dotnet/runtime has it automatically using bot to upgrade dotnet/runtime#85460

The PR #8492 made changes to add explicit dependencies and explicit properties that match those dependencies into the repo. This is required for source-build to work correctly.

Currently getting the dependencies and resolution aren't very straightforward and upgrading roslyn bits causing version downgrades, needs further investigation.

cc @NikolaMilosavljevic

[NikolaMilosavljevic]

Dependencies can be easily upgraded using darc. Here's a command that would make the necessary changes in all required files, i.e. Version.details.xml and Versions.props:

darc update-dependencies --channel ".NET Core Tooling Dev" --source-repo roslyn --version 4.7.0-1.23226.15

Regarding package downgrade - this would be unrelated to the changes I made for source-build. Every package upgrade could cause a conflict with versions of transitive dependencies. The fix usually requires updating the version of the offending dependency. Here's an example of a fix for a similar issue I recently did: microsoft/vstest@37acc70