Update ci.yml

Quick fix UapAppxPackageBuildMode. See the following docs for verification https://docs.microsoft.com/en-us/windows/uwp/packaging/auto-build-package-uwp-apps#configure-the-build-solution-build-task

.github/workflows/ci.yml

@@ -85,7 +85,7 @@ jobs:
       run: msbuild $env:Solution_Path /p:Platform=$env:TargetPlatform /p:Configuration=$env:Configuration /p:UapAppxPackageBuildMode=$env:BuildMode /p:AppxBundle=$env:AppxBundle /p:PackageCertificateKeyFile=$env:SigningCertificate /p:PackageCertificatePassword=${{ secrets.Pfx_Key }}
       env:
         AppxBundle: Never
-        BuildMode: SideLoadOnly
+        BuildMode: SideloadOnly
         Configuration: Debug
         TargetPlatform: ${{ matrix.targetplatform }}