Bump MediatR in /src/content/CleanArchitecture.Blazored/src/Domain

Bumps [MediatR](https://github.com/jbogard/MediatR) from 12.2.0 to 12.4.0.
- [Release notes](https://github.com/jbogard/MediatR/releases)
- [Commits](jbogard/MediatR@v12.2.0...v12.4.0)

---
updated-dependencies:
- dependency-name: MediatR
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

src/content/CleanArchitecture.Blazored/src/Domain/Domain.csproj

@@ -9,7 +9,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="MediatR" Version="12.2.0" />
+      <PackageReference Include="MediatR" Version="12.4.0" />
       <PackageReference Include="NetEscapades.EnumGenerators" Version="1.0.0-beta09"
                         PrivateAssets="all" ExcludeAssets="runtime" />
     </ItemGroup>