deps: bump log4net from 2.0.16 to 3.0.3 in /telemetry/csharp

Bumps [log4net](https://github.com/apache/logging-log4net) from 2.0.16 to 3.0.3.
- [Release notes](https://github.com/apache/logging-log4net/releases)
- [Commits](apache/logging-log4net@rel/2.0.16...rel/3.0.3)

---
updated-dependencies:
- dependency-name: log4net
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

telemetry/csharp/AwsToolkit.Telemetry.Events/AwsToolkit.Telemetry.Events.csproj

@@ -21,7 +21,7 @@
 		<AssemblyOriginatorKeyFile>..\toolkit-telemetry.snk</AssemblyOriginatorKeyFile>
 	</PropertyGroup>
 	<ItemGroup>
-	  <PackageReference Include="log4net" Version="2.0.16" />
+	  <PackageReference Include="log4net" Version="3.0.3" />
 	</ItemGroup>
 	<ItemGroup>
 		<Reference Include="System" />