[docs] Nullable annotations (open-telemetry#5900)

Author: Kielek

docs/logs/redaction/MyRedactionProcessor.cs

@@ -15,33 +15,33 @@ public override void OnEnd(LogRecord logRecord)
         }
     }
 
-    internal sealed class MyClassWithRedactionEnumerator : IReadOnlyList<KeyValuePair<string, object>>
+    internal sealed class MyClassWithRedactionEnumerator : IReadOnlyList<KeyValuePair<string, object?>>
     {
-        private readonly IReadOnlyList<KeyValuePair<string, object>> state;
+        private readonly IReadOnlyList<KeyValuePair<string, object?>> state;
 
-        public MyClassWithRedactionEnumerator(IReadOnlyList<KeyValuePair<string, object>> state)
+        public MyClassWithRedactionEnumerator(IReadOnlyList<KeyValuePair<string, object?>> state)
         {
             this.state = state;
         }
 
         public int Count => this.state.Count;
 
-        public KeyValuePair<string, object> this[int index]
+        public KeyValuePair<string, object?> this[int index]
         {
             get
             {
                 var item = this.state[index];
                 var entryVal = item.Value?.ToString();
                 if (entryVal != null && entryVal.Contains("<secret>"))
                 {
-                    return new KeyValuePair<string, object>(item.Key, "newRedactedValueHere");
+                    return new KeyValuePair<string, object?>(item.Key, "newRedactedValueHere");
                 }
 
                 return item;
             }
         }
 
-        public IEnumerator<KeyValuePair<string, object>> GetEnumerator()
+        public IEnumerator<KeyValuePair<string, object?>> GetEnumerator()
         {
             for (var i = 0; i < this.Count; i++)
             {

docs/logs/redaction/redaction.csproj

@@ -1,8 +1,4 @@
 <Project Sdk="Microsoft.NET.Sdk">
-  <PropertyGroup>
-    <!-- this is temporary. will remove in future PR. -->
-    <Nullable>disable</Nullable>
-  </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="$(RepoRoot)\src\OpenTelemetry.Exporter.Console\OpenTelemetry.Exporter.Console.csproj" />
   </ItemGroup>

docs/trace/customizing-the-sdk/customizing-the-sdk.csproj

@@ -1,8 +1,4 @@
 <Project Sdk="Microsoft.NET.Sdk">
-  <PropertyGroup>
-    <!-- this is temporary. will remove in future PR. -->
-    <Nullable>disable</Nullable>
-  </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="$(RepoRoot)\src\OpenTelemetry.Exporter.Console\OpenTelemetry.Exporter.Console.csproj" />
   </ItemGroup>