Remove roslyn source-build patches that were backported

src/SourceBuild/tarball/patches/roslyn/0003-remove-Microsoft.DotNet-prebuilts.patch

@@ -1,25 +0,0 @@
-From 7260c572b1ce424f7ff3a64aa3227417c6a7a676 Mon Sep 17 00:00:00 2001
-From: Logan Bussell <36081148+lbussell@users.noreply.github.com>
-Date: Fri, 8 Oct 2021 00:56:41 +0000
-Subject: [PATCH] remove Microsoft.DotNet prebuilts
-
-Pull request for applying this patch: https://github.com/dotnet/roslyn/pull/57159
----
- eng/Tools.props | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/eng/Tools.props b/eng/Tools.props
-index 1579b510558..944448855ee 100644
---- a/eng/Tools.props
-+++ b/eng/Tools.props
-@@ -1,6 +1,6 @@
- <Project>
- 
--  <ItemGroup>
-+  <ItemGroup Condition="'$(DotNetBuildFromSource)' != 'true'">
-     <!--
-       This package would normally be restored by the Arcade SDK, but it is not included during restore operations
-       if the -package flag is not also provided during the build. Roslyn separates the restore operation from the
--- 
-2.30.2
-

src/SourceBuild/tarball/patches/roslyn/0004-Disable-apphost-build-of-csi-vbi-for-source-build.patch

@@ -1,41 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Davis Goodin <dagood@microsoft.com>
-Date: Tue, 19 Oct 2021 19:38:52 -0500
-Subject: [PATCH] Disable apphost build of 'csi', 'vbi' for source-build
-
-Creating an apphost for a netcoreapp3.1 project uses the apphost pack as a
-prebuilt. Stopping these projects from creating the apphost removes the prebuilt
-for source-build.
-
-See: https://github.com/dotnet/roslyn/issues/57233
-
-PR: https://github.com/dotnet/roslyn/pull/57306
----
- src/Interactive/csi/csi.csproj | 1 +
- src/Interactive/vbi/vbi.vbproj | 1 +
- 2 files changed, 2 insertions(+)
-
-diff --git a/src/Interactive/csi/csi.csproj b/src/Interactive/csi/csi.csproj
-index 3970bb4e9ea..e96beb550d2 100644
---- a/src/Interactive/csi/csi.csproj
-+++ b/src/Interactive/csi/csi.csproj
-@@ -6,6 +6,7 @@
-     <OutputType>Exe</OutputType>
-     <RootNamespace>CSharpInteractive</RootNamespace>
-     <TargetFrameworks>net6.0;net472</TargetFrameworks>
-+    <UseAppHost Condition="'$(DotNetBuildFromSource)' == 'true'">false</UseAppHost>
-   </PropertyGroup>
-   <ItemGroup Label="Project References">
-     <ProjectReference Include="..\..\Compilers\Core\Portable\Microsoft.CodeAnalysis.csproj" />
-diff --git a/src/Interactive/vbi/vbi.vbproj b/src/Interactive/vbi/vbi.vbproj
-index 5bbdf7f03a7..5f732d71534 100644
---- a/src/Interactive/vbi/vbi.vbproj
-+++ b/src/Interactive/vbi/vbi.vbproj
-@@ -6,6 +6,7 @@
-     <OutputType>Exe</OutputType>
-     <StartupObject>Sub Main</StartupObject>
-     <TargetFrameworks>net6.0;net472</TargetFrameworks>
-+    <UseAppHost Condition="'$(DotNetBuildFromSource)' == 'true'">false</UseAppHost>
-     <RootNamespace></RootNamespace>
-   </PropertyGroup>
-   <ItemGroup Label="Project References">