[Group 6] Enable nullable annotations for Microsoft.Extensions.Logging.Configuration (#67174)

src/libraries/Microsoft.Extensions.Logging.Configuration/ref/Microsoft.Extensions.Logging.Configuration.csproj

 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

src/libraries/Microsoft.Extensions.Logging.Configuration/src/LoggerFilterConfigureOptions.cs

@@ -57,13 +57,13 @@ private void LoadDefaultConfigValues(LoggerFilterOptions options)
             bool GetCaptureScopesValue(LoggerFilterOptions options) => _configuration.GetValue(nameof(options.CaptureScopes), options.CaptureScopes);
         }
 
-        private static void LoadRules(LoggerFilterOptions options, IConfigurationSection configurationSection, string logger)
+        private static void LoadRules(LoggerFilterOptions options, IConfigurationSection configurationSection, string? logger)
         {
-            foreach (System.Collections.Generic.KeyValuePair<string, string> section in configurationSection.AsEnumerable(true))
+            foreach (System.Collections.Generic.KeyValuePair<string, string?> section in configurationSection.AsEnumerable(true))
             {
                 if (TryGetSwitch(section.Value, out LogLevel level))
                 {
-                    string category = section.Key;
+                    string? category = section.Key;
                     if (category.Equals(DefaultCategory, StringComparison.OrdinalIgnoreCase))
                     {
                         category = null;
@@ -74,7 +74,7 @@ private static void LoadRules(LoggerFilterOptions options, IConfigurationSection
             }
         }
 
-        private static bool TryGetSwitch(string value, out LogLevel level)
+        private static bool TryGetSwitch(string? value, out LogLevel level)
         {
             if (string.IsNullOrEmpty(value))
             {

src/libraries/Microsoft.Extensions.Logging.Configuration/src/LoggerProviderConfigurationFactory.cs

@@ -16,15 +16,10 @@ public LoggerProviderConfigurationFactory(IEnumerable<LoggingConfiguration> conf
             _configurations = configurations;
         }
 
-        public IConfiguration GetConfiguration(Type providerType)
+        public IConfiguration GetConfiguration(Type providerType!!)
         {
-            if (providerType == null)
-            {
-                throw new ArgumentNullException(nameof(providerType));
-            }
-
-            string fullName = providerType.FullName;
-            string alias = ProviderAliasUtilities.GetAlias(providerType);
+            string fullName = providerType.FullName!;
+            string? alias = ProviderAliasUtilities.GetAlias(providerType);
             var configurationBuilder = new ConfigurationBuilder();
             foreach (LoggingConfiguration configuration in _configurations)
             {

src/libraries/Microsoft.Extensions.Logging.Configuration/src/Microsoft.Extensions.Logging.Configuration.csproj

@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
+    <Nullable>enable</Nullable>
     <EnableDefaultItems>true</EnableDefaultItems>
     <!-- Use targeting pack references instead of granular ones in the project file. -->
     <DisableImplicitAssemblyReferences>false</DisableImplicitAssemblyReferences>