Bump Serilog from 2.12.0 to 3.1.0

Bumps [Serilog](https://github.com/serilog/serilog) from 2.12.0 to 3.1.0.
- [Release notes](https://github.com/serilog/serilog/releases)
- [Commits](serilog/serilog@v2.12.0...v3.1.0)

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

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

Author: dependabot[bot]

src/Stravaig.Configuration.Diagnostics.Serilog/Stravaig.Configuration.Diagnostics.Serilog.csproj

@@ -48,7 +48,7 @@ Release notes at: $(StravaigReleaseNotes)
     </ItemGroup>
 
     <ItemGroup>
-      <PackageReference Include="Serilog" Version="2.12.0" />
+      <PackageReference Include="Serilog" Version="3.1.0" />
     </ItemGroup>
 
 </Project>

src/Stravaig.Configuration.Diagnostics.Tests/Stravaig.Configuration.Diagnostics.Tests.csproj

@@ -11,7 +11,7 @@
         <PackageReference Include="nunit" Version="3.14.0" />
         <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-        <PackageReference Include="Serilog" Version="2.12.0" />
+        <PackageReference Include="Serilog" Version="3.1.0" />
         <PackageReference Include="Serilog.Formatting.Compact" Version="1.1.0" />
         <PackageReference Include="Serilog.Sinks.Console" Version="4.1.0" /> 
         <PackageReference Include="Serilog.Sinks.TextWriter" Version="2.1.0" />