catchunks: silence new clang-10 warning "final-dtor-non-final-class"

Change-Id: I50052872199fb6ca621f4abe5ab2636735604373
diff --git a/tools/chunks/catchunks/pipeline-interests-fixed.hpp b/tools/chunks/catchunks/pipeline-interests-fixed.hpp
index d7fd95d..e19a25d 100644
--- a/tools/chunks/catchunks/pipeline-interests-fixed.hpp
+++ b/tools/chunks/catchunks/pipeline-interests-fixed.hpp
@@ -62,7 +62,7 @@
  * No guarantees are made as to the order in which segments are fetched or callbacks are invoked,
  * i.e. out-of-order delivery is possible.
  */
-class PipelineInterestsFixed : public PipelineInterests
+class PipelineInterestsFixed final : public PipelineInterests
 {
 public:
   typedef PipelineInterestsFixedOptions Options;