Bump MemoryPack from 1.21.3 to 1.21.4

Bumps [MemoryPack](https://github.com/Cysharp/MemoryPack) from 1.21.3 to 1.21.4.
- [Release notes](https://github.com/Cysharp/MemoryPack/releases)
- [Commits](Cysharp/MemoryPack@1.21.3...1.21.4)

---
updated-dependencies:
- dependency-name: MemoryPack
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Flow.Launcher.Infrastructure/Flow.Launcher.Infrastructure.csproj

@@ -59,7 +59,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="MemoryPack" Version="1.21.3" />
+    <PackageReference Include="MemoryPack" Version="1.21.4" />
     <PackageReference Include="Microsoft.VisualStudio.Threading" Version="17.12.19" />
     <PackageReference Include="Microsoft.Windows.CsWin32" Version="0.3.106">
       <PrivateAssets>all</PrivateAssets>