Bump BenchmarkDotNet from 0.13.0 to 0.13.1 in /Rx.NET/Source
Bumps [BenchmarkDotNet](https://github.com/dotnet/BenchmarkDotNet) from 0.13.0 to 0.13.1.
- [Release notes](https://github.com/dotnet/BenchmarkDotNet/releases)
- [Commits](https://github.com/dotnet/BenchmarkDotNet/compare/v0.13.0...v0.13.1)
---
updated-dependencies:
- dependency-name: BenchmarkDotNet
dependency-type: direct:production
update-type: version-update:semver-patch
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Signed-off-by: dependabot[bot] <[email protected]>