Use dotnet script for MAUI workload restore

[jfversluis]

Description

Switched the .NET MAUI workload restore portion of the script to use the dotnet script to find the right .NET installation rather than assuming the .dotnet folder

Fixes #12284 (comment)

[Copilot]

Pull Request Overview

This PR refactors the MAUI workload installation logic in both build scripts to use the repository's dotnet.sh/dotnet.cmd wrapper scripts instead of directly referencing the .dotnet folder. This ensures the correct .NET installation is used consistently with the rest of the build process.

Key changes:

• Removed hardcoded .dotnet folder paths and environment variable manipulation
• Simplified the installation logic to use existing dotnet.sh/dotnet.cmd wrapper scripts

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
eng/build.sh	Updated to use dotnet.sh wrapper instead of .dotnet/dotnet executable for MAUI workload installation
eng/build.ps1	Updated to use dotnet.cmd wrapper instead of .dotnet/dotnet.exe executable for MAUI workload installation

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 12370

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 12370"

[mitchdenny]

This script doesn't work for me:

[jfversluis]

@mitchdenny looked a bit deeper and I think this is a better setup and follow the pattern in the scripts.

Had to go with -mauirestore in the end because of PowerShell partial parameter matching.

Should be working now for macOS and Windows!