Add exclusion for .slnx file

[marcominerva]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

The Template_Produces_The_Right_Set_Of_FilesAsync test in src/ProjectTemplates/test/Templates.Tests/BaselineTest.cs checks for some files to exclude:

aspnetcore/src/ProjectTemplates/test/Templates.Tests/BaselineTest.cs

Lines 91 to 102 in 3e86bc0

	if (relativePath.EndsWith(".csproj", StringComparison.Ordinal) ||
	relativePath.EndsWith(".fsproj", StringComparison.Ordinal) ||
	relativePath.EndsWith(".props", StringComparison.Ordinal) ||
	relativePath.EndsWith(".sln", StringComparison.Ordinal) ||
	relativePath.EndsWith(".targets", StringComparison.Ordinal) ||
	relativePath.StartsWith("bin/", StringComparison.Ordinal) ||
	relativePath.StartsWith("obj/", StringComparison.Ordinal) ||
	relativePath.Contains("/bin/", StringComparison.Ordinal) ||
	relativePath.Contains("/obj/", StringComparison.Ordinal))
	{
	continue;
	}

Among others, Solution Files (.sln) are excluded. With the introduction of XML Solution Files (.slnx), I believe that this code misses the check for .slnx extension.

.NET Version

10.0.100-preview.6.25358.103

[captainsafia]

@marcominerva Good spot! Your analysis seems accurate. I'd be happy to review/merge a PR if you'll open one.

[javiercn]

I do not think we produce slnx files in our templates at all. Do we? The only one that produces a solution file is the Blazor one. That's likely why we haven't seen it fail on our CI.

We should add this check if/when we decide to start generating slnx solution files. I'm not opposed if we make both changes at the same time.