Add GitHub Actions files to CommunityToolkit.Maui.sln

This follows the same update to `CommunityToolkit.Maui.Samples.sln`

Author: TheCodeTraveler

src/CommunityToolkit.Maui.sln

@@ -8,8 +8,10 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{478D53B4-48B3-4100-BF4D-60F3FC77DE81}"
 	ProjectSection(SolutionItems) = preProject
 		..\.editorconfig = ..\.editorconfig
+		..\.github\workflows\benchmarks.yml = ..\.github\workflows\benchmarks.yml
 		..\Directory.Build.props = ..\Directory.Build.props
 		..\Directory.Build.targets = ..\Directory.Build.targets
+		..\.github\workflows\benchmarks.yml = ..\.github\workflows\benchmarks.yml
 		..\global.json = ..\global.json
 	EndProjectSection
 EndProject