Bump Fake.IO.FileSystem and FSharp.Core

Bumps [Fake.IO.FileSystem](https://github.com/fsprojects/Fake) and [FSharp.Core](https://github.com/dotnet/fsharp). These dependencies needed to be updated together.

Updates `Fake.IO.FileSystem` from 6.0.0 to 6.1.3
- [Release notes](https://github.com/fsprojects/Fake/releases)
- [Changelog](https://github.com/fsprojects/FAKE/blob/master/RELEASE_NOTES.md)
- [Commits](fsprojects/FAKE@6.0.0...6.1.3)

Updates `FSharp.Core` from 9.0.100 to 8.0.301
- [Release notes](https://github.com/dotnet/fsharp/releases)
- [Changelog](https://github.com/dotnet/fsharp/blob/main/release-notes.md)
- [Commits](https://github.com/dotnet/fsharp/commits)

---
updated-dependencies:
- dependency-name: Fake.IO.FileSystem
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: FSharp.Core
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

build.fsproj

@@ -11,7 +11,7 @@
       <PackageReference Include="Fake.Core.Target" Version="6.0.0" />
       <PackageReference Include="Fake.DotNet.Cli" Version="6.0.0" />
       <PackageReference Include="Fake.DotNet.MSBuild" Version="6.0.0" />
-      <PackageReference Include="Fake.IO.FileSystem" Version="6.0.0" />
+      <PackageReference Include="Fake.IO.FileSystem" Version="6.1.3" />
       <PackageReference Include="MSBuild.StructuredLogger" Version="2.2.441" />
       <PackageReference Include="NuGet.Common" Version="6.13.2" />
       <PackageReference Include="NuGet.Packaging" Version="6.9.1" />