build(deps): bump Serilog from 2.12.0 to 3.0.1 in /src (#1019)

Bumps [Serilog](https://github.com/serilog/serilog) from 2.12.0 to 3.0.1.
- [Release notes](https://github.com/serilog/serilog/releases)
- [Changelog](https://github.com/serilog/serilog/blob/dev/CHANGES.md)
- [Commits](serilog/serilog@v2.12.0...v3.0.1)

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

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

src/Splat.Serilog/Splat.Serilog.csproj

@@ -11,7 +11,7 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Serilog" Version="2.12.0" />
+    <PackageReference Include="Serilog" Version="3.0.1" />
     <PackageReference Include="System.Collections.Immutable" Version="7.0.0" />
   </ItemGroup>
   <ItemGroup>