Enable transitive pinning for central package management (microsoft#6225)

## 📖 Description
<!-- Describe what this PR changes, why, and any limitations. -->
This PR enables transitive pinning for central NuGet package management.
This makes the version declared in `Directory.Packages.props` apply to
transitive dependencies, without having to add them as direct
dependencies of a project.

This solves a CG alert about `System.Security.Cryptography.Xml` in
`AppInstallerCLIE2ETests.csproj`.

I'm also removing references that I believe were there only to pin their
version with CPM

## 🔗 References
<!-- Link related issues, PRs, or docs. Use "Resolves #1234" to
auto-close. -->

https://learn.microsoft.com/nuget/consume-packages/central-package-management#transitive-pinning

## 🔍 Validation
<!-- How did you test? List manual steps or note automated test
coverage. -->
Fully untested because a VS update left me unable to build the project
:-)

## ✅ Checklist
<!-- Place an "x" between the brackets to check an item. e.g: [x] -->

- [ ] Signed the [Contributor License
Agreement](https://cla.opensource.microsoft.com)
- [ ] Linked to an issue
- [ ] Updated [Release Notes](../doc/ReleaseNotes.md) (if applicable)
- [ ] Updated documentation (if applicable)
- [ ] Updated [Copilot instructions](.github/copilot-instructions.md)
(if build, architecture, or conventions changed)

## 📋 Issue Type
<!-- Select the type that best describes this PR -->
- [ ] Bug fix
- [ ] Feature
- [ ] Task

###### Microsoft Reviewers: [Open in
CodeFlow](https://microsoft.github.io/open-pr/?codeflow=https://github.com/microsoft/winget-cli/pull/6225)

Author: florelis

src/AppInstallerCLIE2ETests/AppInstallerCLIE2ETests.csproj

@@ -33,8 +33,6 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="System.Data.SqlClient" />
-    <PackageReference Include="System.Text.RegularExpressions" />
   </ItemGroup>
 
   <!-- CsWinRT properties -->

src/Directory.Packages.props

@@ -1,6 +1,7 @@
 <Project>
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+    <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
     <!--
     !!! Remove or update this on the next Microsoft.Windows.CsWinRT package version update. !!!
     -->
@@ -32,7 +33,7 @@
     <PackageVersion Include="System.Private.Uri" Version="4.3.2" />
     <PackageVersion Include="System.Security.Cryptography.Xml" Version="8.0.3" />
     <PackageVersion Include="System.Security.Principal.Windows" Version="5.0.0" />
-    <PackageVersion Include="System.Text.Json" Version="8.0.6" />
+    <PackageVersion Include="System.Text.Json" Version="9.0.6" />
     <PackageVersion Include="System.Text.RegularExpressions" Version="4.3.1" />
     <PackageVersion Include="xunit" Version="2.4.2" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.5" />

src/Microsoft.Management.Configuration.Processor/Microsoft.Management.Configuration.Processor.csproj

@@ -43,12 +43,9 @@
     <PackageReference Include="Microsoft.PowerShell.SDK" GeneratePathProperty="true">
       <ExcludeAssets>contentFiles</ExcludeAssets>
     </PackageReference>
-    <PackageReference Include="Newtonsoft.Json" />
     <PackageReference Include="StyleCop.Analyzers">
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="System.Data.SqlClient" />
-    <PackageReference Include="System.Security.Cryptography.Xml" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(WinGetCsWinRTEmbedded)'!='true'">

src/Microsoft.Management.Configuration.UnitTests/Microsoft.Management.Configuration.UnitTests.csproj

@@ -20,10 +20,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
-    <PackageReference Include="Newtonsoft.Json" />
-    <PackageReference Include="System.Net.Http" />
     <PackageReference Include="System.Private.Uri" />
-    <PackageReference Include="System.Text.RegularExpressions" />
     <PackageReference Include="xunit" />
     <PackageReference Include="xunit.runner.visualstudio">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/WinGetSourceCreator/WinGetSourceCreator.csproj

@@ -9,8 +9,6 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Msix.Utils" />
-    <PackageReference Include="System.Net.Http" />
-    <PackageReference Include="System.Text.RegularExpressions" />
   </ItemGroup>
 
   <ItemGroup>

src/WinGetUtilInterop.UnitTests/WinGetUtilInterop.UnitTests.csproj

@@ -6,14 +6,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" />
     <PackageReference Include="Microsoft.ApplicationInsights" />
     <PackageReference Include="Microsoft.AspNet.WebApi.Client" />
     <PackageReference Include="Microsoft.Msix.Utils" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Moq" />
-    <PackageReference Include="System.Net.Http" />
-    <PackageReference Include="System.Text.RegularExpressions" />
     <PackageReference Include="xunit" />
     <PackageReference Include="xunit.runner.visualstudio" />
     <PackageReference Include="coverlet.collector" />