Update log4net to v2.0.12

Versions 2.0.10 and 2.0.11 appear to be affected by an issue in `Memory-
Appender` which breaks two of our unit tests.

See https://issues.apache.org/jira/projects/LOG4NET/issues/LOG4NET-649.

CHANGELOG.md

@@ -12,7 +12,7 @@ Bugfixes:
 - `private protected` methods are not intercepted (@CrispyDrone, #535)
 - `System.UIntPtr` unsupported (@stakx, #546)
 - DynamicProxy generates two modules when proceeding from a class proxy's protected method to the target, causing an `InvalidOperationException` when saving the generated assembly to disk (@stakx, #569)
-- Upgrade log4net to v2.0.10 (@jonorossi, @stakx, #574)
+- Upgrade log4net to v2.0.12 (@jonorossi, @stakx, #574)
 
 Deprecations:
  - Removed support for the .NET Framework < 4.5 and .NET Standard 1.x. (@stakx, #495, #496)

src/Castle.Core.Tests/Castle.Core.Tests.csproj

@@ -47,7 +47,7 @@
 		<PackageReference Include="NUnit.Console" Version="3.11.1" />
 		<PackageReference Include="NUnit3TestAdapter" Version="3.16.1" />
 		<PackageReference Include="NUnitLite" Version="3.12.0" />
-		<PackageReference Include="log4net" Version="2.0.10" />
+		<PackageReference Include="log4net" Version="2.0.12" />
 		<PackageReference Include="NLog" Version="4.5.0" />
 		<PackageReference Include="Serilog" Version="2.0.0" />
 		<PackageReference Include="Serilog.Sinks.TextWriter" Version="2.0.0" />

src/Castle.Services.Logging.log4netIntegration/Castle.Services.Logging.log4netIntegration.csproj

@@ -25,7 +25,7 @@
 	</ItemGroup>
 
 	<ItemGroup>
-		<PackageReference Include="log4net" Version="2.0.10" />
+		<PackageReference Include="log4net" Version="2.0.12" />
 	</ItemGroup>
 
 	<ItemGroup>