Update test project GUID to SDK-style for consistency with other projects

Co-authored-by: frasermolyneux <34033625+frasermolyneux@users.noreply.github.com>

Author: Copilot

src/XtremeIdiots.Portal.Web.sln

@@ -13,7 +13,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "XtremeIdiots.Portal.Web", "
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "XtremeIdiots.Portal.Integrations.Forums", "XtremeIdiots.Portal.Integrations.Forums\XtremeIdiots.Portal.Integrations.Forums.csproj", "{3E623CA2-1CA2-4B84-BCC9-AB72EABBD2ED}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "XtremeIdiots.Portal.Web.Tests", "XtremeIdiots.Portal.Web.Tests\XtremeIdiots.Portal.Web.Tests.csproj", "{1CE7E855-3968-47A3-AD0F-4B8708E072AA}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "XtremeIdiots.Portal.Web.Tests", "XtremeIdiots.Portal.Web.Tests\XtremeIdiots.Portal.Web.Tests.csproj", "{1CE7E855-3968-47A3-AD0F-4B8708E072AA}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution