.NET: Bump package version to 1.80.1 (#14370)

## Summary
- bump SK .NET packages from 1.80.0 to 1.80.1
- update the package validation baseline from 1.79.0 to 1.80.0

## Rationale
Changes since dotnet-1.80.0 are maintenance updates without new public
APIs or features, so this is a patch release.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: be9e3ab4-e9ee-4871-8b21-a62c2b732f74

Author: SergeyMenshykh

dotnet/nuget/nuget-package.props

@@ -1,15 +1,15 @@
 <Project>
   <PropertyGroup>
     <!-- Central version prefix - applies to all nuget packages. -->
-    <VersionPrefix>1.80.0</VersionPrefix>
+    <VersionPrefix>1.80.1</VersionPrefix>
     <PackageVersion Condition="'$(VersionSuffix)' != ''">$(VersionPrefix)-$(VersionSuffix)</PackageVersion>
     <PackageVersion Condition="'$(VersionSuffix)' == ''">$(VersionPrefix)</PackageVersion>
 
     <Configurations>Debug;Release;Publish</Configurations>
     <IsPackable>true</IsPackable>
 
     <!-- Package validation. Baseline Version should be the latest version available on NuGet. -->
-    <PackageValidationBaselineVersion>1.79.0</PackageValidationBaselineVersion>
+    <PackageValidationBaselineVersion>1.80.0</PackageValidationBaselineVersion>
     <!-- Validate assembly attributes only for Publish builds -->
     <NoWarn Condition="'$(Configuration)' != 'Publish'">$(NoWarn);CP0003</NoWarn>
     <!-- Do not validate reference assemblies -->