Bump PowerShell packages and global.json SDK

The test package bumps keep tripping a `MemberNotNullWhenAttribute`
`TypeLoadException` in seven `OutGridViewWindowIntegrationTests`, even
after clean restores. I pared this back to the updates that still pass
the full suite so we can land the PowerShell refresh without dragging in
the test host regression.

- `Microsoft.PowerShell.SDK` 7.5.4 -> 7.6.1
- `System.Management.Automation` 7.5.4 -> 7.6.1
- `global.json` SDK 10.0.101 -> 10.0.102

I tested with a full `dotnet clean`, `restore`, `build`, and `test`
run against `GraphicalTools.slnx`; all 83 tests pass.

Drafted by Copilot (GPT-5.5).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: andyleejordan

Directory.Packages.props

@@ -1,8 +1,8 @@
 <Project>
   <ItemGroup>
-    <PackageVersion Include="Microsoft.PowerShell.SDK" Version="7.5.4" />
+    <PackageVersion Include="Microsoft.PowerShell.SDK" Version="7.6.1" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />
-    <PackageVersion Include="System.Management.Automation" Version="7.5.4" />
+    <PackageVersion Include="System.Management.Automation" Version="7.6.1" />
     <PackageVersion Include="Terminal.Gui" Version="2.1.0" />
     <!-- Test dependencies -->
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />

global.json

@@ -1,6 +1,6 @@
 {
     "sdk": {
-      "version": "10.0.101",
+      "version": "10.0.102",
       "rollForward": "latestFeature",
       "allowPrerelease": false
     }