Remove experimental from Font Install, Uninstall, and source

[dkbennett]

This removes experimental from font install, uninstall, and source.

The font command remains experimental and is not required to install or remove fonts, which use the normal install and uninstall flow for a WinGet package.

• I have signed the Contributor License Agreement.
• I have updated the Release Notes.
• This pull request is related to an issue.

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Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull Request Overview

This PR removes the experimental flag from Font Install, Uninstall operations and font source support, making these features generally available. The font command itself remains experimental.

• Removes experimental feature checks from font install/uninstall workflows
• Updates font source policy to no longer require experimental feature flag
• Updates documentation to reflect font features are now non-experimental

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/AppInstallerRepositoryCore/SourcePolicy.cpp	Removes experimental feature requirement for WinGet font source
src/AppInstallerCLIE2ETests/GroupPolicy.cs	Removes experimental font feature configuration from test
src/AppInstallerCLICore/Workflows/UninstallFlow.cpp	Removes experimental feature check from font uninstall workflow
src/AppInstallerCLICore/Workflows/InstallFlow.cpp	Removes experimental feature check from font install workflow
doc/ReleaseNotes.md	Updates release notes to document font features as non-experimental

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