Drop outdated comment about LogEntry copyability.

PiperOrigin-RevId: 489569565
Change-Id: Ia08c0c956a672ad435885c68f3e4a3de0405dad1

absl/log/log_entry.h

@@ -49,7 +49,7 @@ class LogMessage;
 // Represents a single entry in a log, i.e., one `LOG` statement or failed
 // `CHECK`.
 //
-// `LogEntry` is copyable and thread-compatible.
+// `LogEntry` is thread-compatible.
 class LogEntry final {
  public:
   using tid_t = log_internal::Tid;