[release/10.0] Switch back to net8.0 for tools

[AndriySvyryd]

Fixes #37201

Description

Up to 9.0 EF targeted the lowest supported TFM. In 10.0 we decided to only target the latest one to make the versioning story simpler for users. However, the tools should have continued to target the lowest TFM because they are decoupled from the other NuGet packages and frequently used with older versions.

Customer impact

Exception when trying to use the EF tools on a project targeting net8.0 or net9.0

How found

Customer reported on 10.0.0

Regression

Yes, from 9.0.0. Introduced in #35488

Testing

Tested manually and these are the only parts of EF 10 that are expected to work on net8.0 and net9.0

Risk

Low, only design-time tools are affected by the change.

[Copilot]

Pull Request Overview

This PR switches the EF Core tools back to targeting .NET 8.0 (from .NET 10.0) on the release/10.0 branch by replacing $(DefaultNetCoreTargetFramework) with $(NetToolMinimum) and $(NetToolCurrent) properties. The changes update project target frameworks and package manifests to reference net8.0 instead of net10.0.

Key changes:

• Update tool projects to use $(NetToolMinimum) instead of $(DefaultNetCoreTargetFramework)
• Update hardcoded framework version strings from net10.0 to net8.0 in code and scripts
• Update NuGet package specifications to use the new MSBuild properties

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/ef/ef.csproj	Changed TargetFrameworks from $(DefaultNetCoreTargetFramework) to $(NetToolMinimum)
src/dotnet-ef/dotnet-ef.nuspec	Updated target paths to use lowercase $targetFramework$ variable; contains a typo on line 19
src/dotnet-ef/dotnet-ef.csproj	Changed TargetFramework from $(DefaultNetCoreTargetFramework) to $(NetToolMinimum)
src/dotnet-ef/RootCommand.cs	Updated preprocessor directive from NET10_0 to NET8_0 and hardcoded path from net10.0 to net8.0
src/EFCore.Tools/tools/EntityFrameworkCore.psm1	Updated ef.dll path from net10.0 to net8.0
src/EFCore.Tools/EFCore.Tools.csproj	Changed TargetFramework from $(DefaultNetCoreTargetFramework) to $(NetToolMinimum)
src/EFCore.Tasks/EFCore.Tasks.nuspec	Updated to use $(NetToolCurrent) and $(NetToolMinimum) properties; contains inconsistency on line 20
src/EFCore.Tasks/EFCore.Tasks.csproj	Changed TargetFrameworks to use $(NetToolCurrent) and added NuspecProperty entries for both new properties

[AndriySvyryd]

cc @artl93

[artl93]

Last week we talked about getting more coverage on these scenarios by testing htem ourselves. Do we know if this is the end of targeting concerns?

[AndriySvyryd]

We are tracking test coverage in #17018 and #33136. However, only part of this regression would have been caught as we typically don't use test boxes without the latest .NET SDK

[artl93]

Approved based on the explanation that there was an intentional change that mistakenly included impacting these components. Customer reported regression.