remove RateVsTime histograms

I have replaced the RateVsTime histograms on Monet with trend plots using the counters, so here I remove the histograms from Allen. I also removed the additions to constants that the histograms needed that are no longer used.

device/selections/Hlt1/include/GatherSelections.cuh

@@ -86,10 +86,8 @@ namespace gather_selections {
 
     void monitor_operator(const ArgumentReferences<Parameters>& arguments, gsl::span<bool>) const;
 
-    void monitor_postscaled_operator(
-      const ArgumentReferences<Parameters>& arguments,
-      const Constants&,
-      gsl::span<bool>) const;
+    void monitor_postscaled_operator(const ArgumentReferences<Parameters>& arguments, const Constants&, gsl::span<bool>)
+      const;
 
   private:
     mutable std::vector<std::unique_ptr<Gaudi::Accumulators::Counter<>>> m_pass_counters;