Move Latch out of this PR

Latch has no user here; it moves to the Jackson NoSuchFieldError fix
(#12670), which is where it is used. ClassLatch's Javadoc no longer
links to it.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Author: dougqh

internal-api/src/main/java/datadog/trace/util/ClassLatch.java

@@ -5,7 +5,8 @@
 /**
  * A per-class latch for an operation that, once it has failed for a class, will fail the same way
  * for every instance of that class: an interface method the class does not implement, for example.
- * For a failure that is the same for everyone, use {@link Latch}.
+ * A failure that is the same for everyone, whatever the class, needs only a single flag and no
+ * per-class state.
  *
  * <p>Intended as a {@code static final} anonymous subclass, one per call site and per operation: a
  * class lacking one method says nothing about another, so latches must not be shared. As a constant