[release/10.0] Fix Microsoft.EntityFrameworkCore.Tools for net8.0

[Copilot]

Fixes #37515

Description
#37207 was intended to allow the EF tools to run for apps targeting net8.0, however the Microsoft.EntityFrameworkCore.Tools NuGet package does not specify a target framework, and it depends on Microsoft.EntityFrameworkCore.Design 10.0.0 which only targets net10.0

Customer impact
Customers can't use Microsoft.EntityFrameworkCore.Tools 10.0.x for apps targeting net8.0, but some tooling that analyzes NuGet packages incorrectly interpret the lack of a target framework specification and select this version even when targeting net8.0.

How found
3 customer reports on 10.0.x

Regression
Not technically, but it completes the fix in #37207 that was for a regression. Also, a change from #33049 is reverted to make the supported TFM explicit

Testing
Tested manually

Risk
Low. The change is mostly reverting to the state the package was for EF 8

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Microsoft.EntityFrameworkCore.Tools missing target framework</issue_title>
<issue_description>### What problem are you trying to solve?

NuGet package: Microsoft.EntityFrameworkCore.Tools here

The packages does not have a target framework, but it depend on Microsoft.EntityFrameworkCore.Design that only have a target framework .net 10

Could you make Microsoft.EntityFrameworkCore.Tools have the same target framework since some tools assume that no framework mean it works for all frameworks?

Describe the solution you'd like

Microsoft.EntityFrameworkCore.Tools has a target framework.
Link to source code link to this repo instead of https://github.com/dotnet/dotnet</issue_description>

<agent_instructions>Add back the lib/net8.0/_._ file removed in 52f37b3#diff-124e1ace0877746700e5049053b50e061fdeeaa10880199dbeb3078abe429ac5 to be able to specify net8.0 framework.
Make the minimum version for the Microsoft.EntityFrameworkCore.Design dependency 8.0.0, but allow newer major versions</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@AndriySvyryd > The packages does not have a target framework, but it depend on Microsoft.EntityFrameworkCore.Design that only have a target framework .net 10

@HenrikSommer-Energinet I do not understand what you are trying to communicate. Are you experiencing any issues?

Maybe it is related as mine .net thinks I am still targetting .Net9, not 10.

@Levvy055 You need to make sure all your (transitive) dependencies get the same version of Microsoft.CodeAnalysis.* packages (5.0.0). You can override the versions by referencing them directly or by using Central Package Management</comment_new>

---

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[AndriySvyryd]

@copilot Update progress by rewriting the PR summary using this template:

Fixes #{number}

**Description**
{Issue description}

**Customer impact**
{How does the reported issue affects customer's app? Are there workarounds?}

**How found**
{Was it customer reported or found during verification? How many customers are affected?}

**Regression**
{Is it a regression from a released version? Which one?}

**Testing**
{How the changes were tested}

**Risk**
{Low/Medium/High, argument why}

[Copilot]

@copilot Update progress by rewriting the PR summary using this template:

Updated PR description with the requested template format.

[Copilot]

Pull request overview

Adjusts the Microsoft.EntityFrameworkCore.Tools NuGet package metadata/content so it’s correctly recognized as supporting net8.0, avoiding incorrect tooling assumptions caused by having no lib/ target framework folder, and loosens the Design dependency from the EF 10 version to a minimum that can work for net8.0 scenarios.

Changes:

• Add lib/net8.0/_._ to make the package’s supported TFM explicit (net8.0).
• Update the .nuspec to include lib/** in the packed files.
• Change the Microsoft.EntityFrameworkCore.Design dependency from $Version$ to a minimum of 8.0.0.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
src/EFCore.Tools/lib/net8.0/.	Adds a net8.0 lib placeholder to ensure the package advertises an explicit target framework.
src/EFCore.Tools/EFCore.Tools.nuspec	Packs the new lib/ content and lowers the minimum Design dependency version to allow net8-compatible restores.

[artl93]

Customer reported, critical scenario.
Can we do something proactive to make sure this follows the LTS versioning? this seems like it would break often - we need to make sure this is handled as a part of each release, right?

(Approved otherwise)

[AndriySvyryd]

Customer reported, critical scenario. Can we do something proactive to make sure this follows the LTS versioning? this seems like it would break often - we need to make sure this is handled as a part of each release, right?

Yes, this dependency shouldn't be needed in the first place if the app is referencing Microsoft.EntityFrameworkCore.Design already (common and recommended when using the EF tools). #37739 tracks removing it (it would be technically a breaking change for the apps without this reference)