Bump System.Memory from 4.5.4 to 4.5.5

Bumps [System.Memory](https://github.com/dotnet/corefx) from 4.5.4 to 4.5.5.
- [Release notes](https://github.com/dotnet/corefx/releases)
- [Commits](https://github.com/dotnet/corefx/commits)

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

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

Author: dependabot[bot]

NSF2SQL/packages.config

@@ -9,7 +9,7 @@
   <package id="MySql.Data" version="8.1.0" targetFramework="net472" />
   <package id="SSH.NET" version="2020.0.2" targetFramework="net472" />
   <package id="System.Buffers" version="4.5.1" targetFramework="net472" />
-  <package id="System.Memory" version="4.5.4" targetFramework="net472" />
+  <package id="System.Memory" version="4.5.5" targetFramework="net472" />
   <package id="System.Numerics.Vectors" version="4.5.0" targetFramework="net472" />
   <package id="System.Runtime.CompilerServices.Unsafe" version="6.0.0" targetFramework="net472" />
   <package id="WindowsAPICodePack-Core" version="1.1.2" targetFramework="net472" />