Review net 11 TFM update for opportunities for improvement of SDK codebase

The primary steps are covered here:
https://github.com/dotnet/sdk/issues/50295

The high level bulk items are the following.
1. Branding
2. Bundled Versions
3. Retarget SDK
4. Retarget tests (see Toolsetinfo.cs)
5. Retarget templates

From that, we should investigate when those can be done (especially wrt runtime repo timing), can we create any copilot instruction files to reduce costs for any of those, and what improvements we can make in the SDK to reduce long term-costs.

Primary ideas

- Investigate watch tests for better stability across TFM
- Investigate templating tests to reduce their fragility to TFM (and frankly other) output updates