Generator snapshot test builds warn that Verify cannot choose among solution files #7419

Summary

Building the core source generator snapshot tests emits a Verify warning because it discovers three solution files and cannot choose a solution directory or name. Configure these properties explicitly so routine test builds do not emit this warning.

Reproduction

At ca4437c, with .NET SDK 10.0.403 on macOS arm64, run:

dotnet test --project tests/TUnit.Core.SourceGenerator.Tests --framework net10.0

Expected and actual

Expected: Verify can identify the solution context without warnings.

Actual: Verify 33.3.4's buildTransitive/Verify.props reports that TUnit.CI.slnx, TUnit.Dev.slnx and TUnit.slnx make solution discovery ambiguous. It recommends setting SolutionDir and SolutionName explicitly.

Please configure the test build's Verify solution context.