remove runtime patch that was already addressed upstream

src/SourceBuild/tarball/patches/runtime/0003-Disable-package-validation-in-source-build-for-relia.patch

@@ -1,31 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Davis Goodin <dagood@microsoft.com>
-Date: Tue, 26 Oct 2021 13:24:57 -0500
-Subject: [PATCH] Disable package validation in source-build for reliability
-
-See comment in diff.
-
-Upstream PR: https://github.com/dotnet/runtime/pull/60881
----
- eng/packaging.targets | 8 +++++++-
- 1 file changed, 7 insertions(+), 1 deletion(-)
-
-diff --git a/eng/packaging.targets b/eng/packaging.targets
-index ecf74672ac8..0a04191182d 100644
---- a/eng/packaging.targets
-+++ b/eng/packaging.targets
-@@ -1,7 +1,13 @@
- <Project>
- 
-   <PropertyGroup>
--    <EnablePackageValidation>true</EnablePackageValidation>
-+    <!--
-+      Package validation causes flaky errors during the build. Validation isn't useful during
-+      source-build (it is only a guardrail for devs), so disable it during source-build to avoid the
-+      impact on build reliability. https://github.com/dotnet/runtime/issues/60883 tracks fixing the
-+      flakiness and removing this condition.
-+    -->
-+    <EnablePackageValidation Condition="'$(DotNetBuildFromSource)' != 'true'">true</EnablePackageValidation>
-     <!-- Don't restore prebuilt packages during sourcebuild. -->
-     <DisablePackageBaselineValidation Condition="'$(DotNetBuildFromSource)' == 'true'">true</DisablePackageBaselineValidation>
-     <PackageValidationBaselineVersion Condition="'$(PackageValidationBaselineVersion)' == ''">$(NetCoreAppLatestStablePackageBaselineVersion)</PackageValidationBaselineVersion>