Move to an 8.0.100-alpha SDK (#44234)

* Move to an 8.0.100-alpha SDK
* Move to correct SDK version
  - my how I love committing suggestions in a batch
* Work around dotnet/sdk#28016
  - see also dotnet/sdk#28049

global.json

@@ -1,9 +1,9 @@
 {
   "sdk": {
-    "version": "7.0.100-rtm.22471.17"
+    "version": "8.0.100-alpha.1.22478.15"
   },
   "tools": {
-    "dotnet": "7.0.100-rtm.22471.17",
+    "dotnet": "8.0.100-alpha.1.22478.15",
     "runtimes": {
       "dotnet/x86": [
         "$(MicrosoftNETCoreBrowserDebugHostTransportVersion)"

src/Servers/HttpSys/test/FunctionalTests/Microsoft.AspNetCore.Server.HttpSys.FunctionalTests.csproj

@@ -6,6 +6,8 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <!-- Required for System.Net.Quic which has a preview API in .NET 7 -->
     <EnablePreviewFeatures>true</EnablePreviewFeatures>
+    <!-- Required because 8.0.0 SDK no longer considers net7.0 the current TFM. -->
+    <GenerateRequiresPreviewFeaturesAttribute>true</GenerateRequiresPreviewFeaturesAttribute>
   </PropertyGroup>
 
   <ItemGroup>

src/Servers/IIS/IIS/test/IIS.FunctionalTests/IIS.FunctionalTests.csproj

@@ -9,6 +9,8 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <!-- Required for System.Net.Quic which has a preview API in .NET 7 -->
     <EnablePreviewFeatures>true</EnablePreviewFeatures>
+    <!-- Required because 8.0.0 SDK no longer considers net7.0 the current TFM. -->
+    <GenerateRequiresPreviewFeaturesAttribute>true</GenerateRequiresPreviewFeaturesAttribute>
   </PropertyGroup>
 
   <Import Project="../FunctionalTest.props" />

src/Servers/Kestrel/Transport.Quic/test/Microsoft.AspNetCore.Server.Kestrel.Transport.Quic.Tests.csproj

@@ -6,6 +6,8 @@
     <ServerGarbageCollection>true</ServerGarbageCollection>
     <!-- Required for System.Net.Quic which has a preview API in .NET 7 -->
     <EnablePreviewFeatures>true</EnablePreviewFeatures>
+    <!-- Required because 8.0.0 SDK no longer considers net7.0 the current TFM. -->
+    <GenerateRequiresPreviewFeaturesAttribute>true</GenerateRequiresPreviewFeaturesAttribute>
   </PropertyGroup>
 
   <ItemGroup>

src/Servers/Kestrel/samples/WebTransportInteractiveSampleApp/WebTransportInteractiveSampleApp.csproj

@@ -5,6 +5,8 @@
     <AspNetCoreHostingModel>OutOfProcess</AspNetCoreHostingModel>
     <!-- Turn on preview features so we can use Http3 -->
     <EnablePreviewFeatures>True</EnablePreviewFeatures>
+    <!-- Required because 8.0.0 SDK no longer considers net7.0 the current TFM. -->
+    <GenerateRequiresPreviewFeaturesAttribute>true</GenerateRequiresPreviewFeaturesAttribute>
   </PropertyGroup>
 
   <ItemGroup>

src/Servers/Kestrel/samples/WebTransportSampleApp/WebTransportSampleApp.csproj

@@ -4,6 +4,8 @@
     <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
     <!-- Turn on preview features so we can use Http3 -->
     <EnablePreviewFeatures>True</EnablePreviewFeatures>
+    <!-- Required because 8.0.0 SDK no longer considers net7.0 the current TFM. -->
+    <GenerateRequiresPreviewFeaturesAttribute>true</GenerateRequiresPreviewFeaturesAttribute>
   </PropertyGroup>
 
   <ItemGroup>