Remove reference to DEBUG value (#5384)

The truth is that the tooling doesn't use `Condition` for anything right now and the only applicable issue has been closed: dotnet/linker#1231.

Author: MichalStrehovsky

xml/System.Diagnostics.CodeAnalysis/DynamicDependencyAttribute.xml

@@ -194,7 +194,7 @@ This attribute can be used to inform tooling of a dependency that is otherwise n
  <ReturnType>System.String</ReturnType>
  </ReturnValue>
  <Docs>
- <summary>Gets or sets the condition in which the dependency is applicable, for example, "DEBUG".</summary>
+ <summary>Gets or sets the condition in which the dependency is applicable.</summary>
  <value>To be added.</value>
  <remarks>To be added.</remarks>
  </Docs>