Update TOC files to change ".NET 10 Preview" to ".NET 10"

Co-authored-by: adegeo <67293991+adegeo@users.noreply.github.com>

Author: Copilot

dotnet-desktop-guide/winforms/toc.yml

@@ -7,7 +7,7 @@ items:
   items:
   - name: Overview
     href: whats-new/index.md
-  - name: What's new in .NET 10 Preview
+  - name: What's new in .NET 10
     href: whats-new/net100.md
   - name: What's new in .NET 9.0
     href: whats-new/net90.md

dotnet-desktop-guide/wpf/toc.yml

@@ -16,7 +16,7 @@ items:
   items:
   - name: Overview
     href: whats-new/index.md
-  - name: What's new in .NET 10 Preview
+  - name: What's new in .NET 10
     href: whats-new/net100.md
   - name: What's new in .NET 9
     href: whats-new/net90.md