Update workflow to windows-2025 and add to solution items

Changed GitHub Actions workflow to use windows-2025 runner and updated the solution file to include the workflow YAML under Solution Items for easier access.

Author: chuongmep

.github/workflows/Workflow.yml

@@ -10,8 +10,8 @@ on:
 
 jobs:
   windows:
-    name: windows-2022
-    runs-on: windows-2022
+    name: windows-2025
+    runs-on: windows-2025
     steps:
       - name: Checkout
         uses: actions/checkout@v1

AddInManager.sln

@@ -7,6 +7,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Project", "Project", "{A8C6
 	ProjectSection(SolutionItems) = preProject
 		CHANGELOG.md = CHANGELOG.md
 		Readme.MD = Readme.MD
+		.github\workflows\Workflow.yml = .github\workflows\Workflow.yml
 	EndProjectSection
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Installer", "Installer\Installer.csproj", "{E3C87D34-638C-47A0-A73A-D967B119458D}"