## Summary
- update `src/GlobalTools/PowerShell/PowerShell.csproj` from `net10.0` to `net11.0`
- align the cross-platform Global Tool with `Microsoft.PowerShell.SDK` and the Windows Global Tool
- fix Release Branch Prep vulnerability-scanner restore failures after moving release/v7.7.0 to .NET 11

## Validation
- `dotnet restore src\GlobalTools\PowerShell\PowerShell.csproj --runtime win-x64 /p:NuGetAudit=false`

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# PR Summary

Explicitly maps `VSS_NUGET_EXTERNAL_FEED_ENDPOINTS` into the environment of both global-tool steps that invoke `dotnet`: the restore/publish step and the later pack step.

## PR Context

Packaging build 738142 failed in all eight global-tool RID matrix jobs with NU1301 / HTTP 401 while restoring from the `powershell-net-11-early-access` Azure Artifacts feed.

`.pipelines/templates/insert-nuget-config-azfeed.yml` creates `VSS_NUGET_EXTERNAL_FEED_ENDPOINTS` as a secret pipeline variable, but Azure Pipelines does not automatically export secret variables into subsequent task environments. The global-tool publish step only mapped `__DOTNET_RUNTIME_FEED_KEY`, so the Azure Artifacts Credential Provider could not read the endpoint credentials. This change explicitly exports the secret variable to restore/publish and pack for consistent authenticated NuGet access.

Validation:
- `git diff --check` — passed
- `python -c "import pathlib, yaml; p=pathlib.Path(r'.pipelines\\templates\\step\\globaltool-rid-pack.yml'); yaml.safe_load(p.read_text(encoding='utf-8')); print('YAML parsed successfully')"` — passed (`YAML parsed successfully`)

## PR Checklist

- [x] [PR has a meaningful title](https://github.com/PowerShell/PowerShell/blob/master/.github/CONTRIBUTING.md#pull-request---submission)
  - Use the present tense and imperative mood when describing your changes
- [x] [Summarized changes](https://github.com/PowerShell/PowerShell/blob/master/.github/CONTRIBUTING.md#pull-request---submission)
- [x] [Make sure all `.h`, `.cpp`, `.cs`, `.ps1` and `.psm1` files have the correct copyright header](https://github.com/PowerShell/PowerShell/blob/master/.github/CONTRIBUTING.md#pull-request---submission)
- [x] This PR is ready to merge. If this PR is a work in progress, please open this as a [Draft Pull Request and mark it as Ready to Review when it is ready to merge](https://docs.github.com/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/about-pull-requests#draft-pull-requests).
- **[Breaking changes](https://github.com/PowerShell/PowerShell/blob/master/.github/CONTRIBUTING.md#making-breaking-changes)**
  - [x] None
  - **OR**
  - [ ] [Experimental feature(s) needed](https://github.com/MicrosoftDocs/PowerShell-Docs/blob/main/reference/7.5/Microsoft.PowerShell.Core/About/about_Experimental_Features.md)
    - [ ] Experimental feature name(s):
- **User-facing changes**
  - [x] Not Applicable
  - **OR**
  - [ ] [Documentation needed](https://github.com/PowerShell/PowerShell/blob/master/.github/CONTRIBUTING.md#pull-request---submission)
    - [ ] Issue filed:
- **Testing - New and feature**
  - [x] N/A or can only be tested interactively
  - **OR**
  - [ ] [Make sure you've added a new test if existing tests do not effectively test the code changed](https://github.com/PowerShell/PowerShell/blob/master/.githu...