Add missing WPF memory improvement AppContext switches (#49535)

* Initial plan

* Add missing AppContext switches for WPF memory improvements

Co-authored-by: gewarren <[email protected]>

* Update docs/framework/configure-apps/file-schema/runtime/appcontextswitchoverrides-element.md

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: gewarren <[email protected]>

Author: Copilot

docs/framework/configure-apps/file-schema/runtime/appcontextswitchoverrides-element.md

@@ -61,6 +61,8 @@ Defines one or more switches used by the <xref:System.AppContext> class to provi
 | Switch name | Description | Introduced |
 |-------------|-------------|------------|
 |`Switch.MS.Internal.`<br/>`DoNotApplyLayoutRoundingToMarginsAndBorderThickness`|Controls whether Windows Presentation Foundation uses legacy a algorithm for control layout. For more information, see [Mitigation: WPF Layout](../../../migration-guide/mitigation-wpf-layout.md).|.NET Framework 4.6|
+| `Switch.MS.Internal.`<br/>`EnableCleanupSchedulingImprovements` | When set to `true`, improves the cleanup scheduling behavior of the weak-event pattern. | |
+| `Switch.MS.Internal.`<br/>`EnableWeakEventMemoryImprovements` | When set to `true`, improves the memory allocation behavior of the weak-event pattern. | |
 |`Switch.MS.Internal.`<br/>`UseSha1AsDefaultHashAlgorithmForDigitalSignatures`|Controls whether the default algorithm used for signing parts of a package by PackageDigitalSignatureManager is SHA1 or SHA256.<br>Due to collision problems with SHA1, Microsoft recommends SHA256.|.NET Framework 4.7.1|
 |`Switch.System.Activities.`<br/>`UseMD5CryptoServiceProviderForWFDebugger`|When set to `false`, allows debugging of XAML-based workflow projects with Visual Studio when FIPS is enabled. Without it, a <xref:System.NullReferenceException> is thrown in calls to methods in the System.Activities assembly.|.NET Framework 4.7|
 |`Switch.System.Activities.`<br/>`UseMD5ForWFDebugger`|Controls whether the checksum for a workflow instance in the debugger uses MD5 or SHA1. | .NET Framework 4.7|