chore(deps): update dependency mediatr to v12.4.0 (#947)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [MediatR](https://togithub.com/jbogard/MediatR) | `12.3.0` -> `12.4.0`
|
[![age](https://developer.mend.io/api/mc/badges/age/nuget/MediatR/12.4.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![adoption](https://developer.mend.io/api/mc/badges/adoption/nuget/MediatR/12.4.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
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|
[![confidence](https://developer.mend.io/api/mc/badges/confidence/nuget/MediatR/12.3.0/12.4.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|

---

### Release Notes

<details>
<summary>jbogard/MediatR (MediatR)</summary>

###
[`v12.4.0`](https://togithub.com/jbogard/MediatR/releases/tag/v12.4.0)

#### What's Changed

- Add Support For Generic Handlers With Multiple Generic Type Parameters
by [@&#8203;zachpainter77](https://togithub.com/zachpainter77) in
[https://github.com/jbogard/MediatR/pull/1048](https://togithub.com/jbogard/MediatR/pull/1048)

**Full Changelog**:
LuckyPennySoftware/MediatR@v12.3.0...v12.4.0

</details>

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src/Digdir.Domain.Dialogporten.Application/Digdir.Domain.Dialogporten.Application.csproj

@@ -13,7 +13,7 @@
         <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.0"/>
         <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="8.0.0"/>
         <PackageReference Include="FluentValidation.DependencyInjectionExtensions" Version="11.9.2"/>
-        <PackageReference Include="MediatR" Version="12.3.0"/>
+        <PackageReference Include="MediatR" Version="12.4.0"/>
         <PackageReference Include="Npgsql" Version="8.0.3"/>
         <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="8.0.4"/>
         <PackageReference Include="NSec.Cryptography" Version="24.4.0"/>