Use .NET 7 SDK

[Youssef1313]

GitHub Issue (If applicable): closes #10120

PR Type

What kind of change does this PR introduce?

What is the current behavior?

What is the new behavior?

PR Checklist

Please check if your PR fulfills the following requirements:

• Docs have been added/updated which fit documentation template (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Validated PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Associated with an issue (GitHub or internal) and uses the automatic close keywords.
• Commits must be following the Conventional Commits specification.

Other information

Internal Issue (If applicable):

[gitpod-io]

[jeromelaban]

This change is going to impact the net6-mobile targets, which are not yet tested completely. Let's see what the build is saying first.

[Youssef1313]

This change is going to impact the net6-mobile targets, which are not yet tested completely. Let's see what the build is saying first.

Sure. Let's get the build green first and discuss any potential issues after that.

[Youssef1313]

Workload installation failed: microsoft.android.sdk.darwin::33.0.0-rc.1.136 is not found in NuGet feeds https://api.nuget.org/v3/index.json".

@jeromelaban Do you know what controls the requested version? Is it on Microsoft side? I guess they should have this version on NuGet.org or bump the requested version to 33.0.0-rc.1.151 which is already on NuGet.org.

Edit: dotnet/installer#14776

[jeromelaban]

It's controlled by Microsoft's workloads, that why I mentioned that we should wait for Microsoft's release of the MAUI 7 RC2 workloads. You can pause this PR for now.

[Youssef1313]

It's controlled by Microsoft's workloads, that why I mentioned that we should wait for Microsoft's release of the MAUI 7 RC2 workloads.

I downgraded the version used in this PR to RC1 thinking it would address your concern. But still even in RC1 Microsoft is using a package version that's not on NuGet.org.

I can wait for MAUI use of RC2 if they'll fix the issue at that time.

[jeromelaban]

We cannot merge this PR as is, as the .NET 6 portion of the build is building with .NET 7, causing this issue: dotnet/sdk#30103. The .NET 6 portion needs to build explicitly using .NET 6 installed, even if the build passes with .NET 7. We'll reevaluate when we can drop Xamarin and net6, likely during this year around .NET 8.

[jeromelaban]

That being said, there are some portions of this PR that can be extracted (some legacy steps to remove).

[Youssef1313]

@jeromelaban Is it good with the last commit?

[jeromelaban]

No, this will not be enough. The uno-check versions must also be different and .NET 7 must not be installed at all when building for net6 jobs.

[Youssef1313]

@jeromelaban It should be good now :)

[jeromelaban]

Looking good!