build(deps): Bump Serilog from 3.0.1 to 3.1.1 (#1267)

Bumps [Serilog](https://github.com/serilog/serilog) from 3.0.1 to 3.1.1.
- [Release notes](https://github.com/serilog/serilog/releases)
- [Commits](serilog/serilog@v3.0.1...v3.1.1)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

tests/bunit.testassets/bunit.testassets.csproj

@@ -13,7 +13,7 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="Serilog" Version="3.0.1" />
+		<PackageReference Include="Serilog" Version="3.1.1" />
 		<PackageReference Include="Serilog.Expressions" Version="3.4.1" />
 		<PackageReference Include="xunit.extensibility.execution" Version="2.5.2" />
 		<PackageReference Include="xunit.abstractions" Version="2.0.3" />