Bump Serilog from 2.12.0 to 4.2.0

Bumps [Serilog](https://github.com/serilog/serilog) from 2.12.0 to 4.2.0.
- [Release notes](https://github.com/serilog/serilog/releases)
- [Commits](serilog/serilog@v2.12.0...v4.2.0)

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

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

src/Serilog.Sinks.Grafana.Loki/Serilog.Sinks.Grafana.Loki.csproj

@@ -24,7 +24,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Serilog" Version="2.12.0" />
+        <PackageReference Include="Serilog" Version="4.2.0" />
         <PackageReference Include="System.Text.Json" Version="4.7.0" />
     </ItemGroup>