Bump System.Memory from 4.5.5 to 4.6.0 in /src/net

Bumps [System.Memory](https://github.com/dotnet/maintenance-packages) from 4.5.5 to 4.6.0.
- [Release notes](https://github.com/dotnet/maintenance-packages/releases)
- [Commits](https://github.com/dotnet/maintenance-packages/commits)

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

Signed-off-by: dependabot[bot] <[email protected]>

src/net/KNet.Serialization.MessagePack/KNet.Serialization.MessagePack.csproj

@@ -18,7 +18,7 @@
 		<None Include="..\..\documentation\articles\usageSerDes.md" Pack="true" PackagePath="\" />
 	</ItemGroup>
 	<ItemGroup Condition="'$(TargetFramework)' == 'net462'">
-		<PackageReference Include="System.Memory" Version="4.5.5" />
+		<PackageReference Include="System.Memory" Version="4.6.0" />
 	</ItemGroup>
 	<ItemGroup>
 	  <PackageReference Include="MessagePack" Version="2.5.187" />