Fix Clang warning about unused functions

only affecting standalone build of public headers

Event/TrackEvent/include/Event/UTSectorHelper.h

@@ -70,14 +70,14 @@ namespace LHCb::UTDAQ {
     //=============================================================================
     // -- Helper for non-trivial index calculation
     //=============================================================================
-    int boundsIndex( const int maxNumSectors, const int layer, const int offset ) {
+    [[maybe_unused]] int boundsIndex( const int maxNumSectors, const int layer, const int offset ) {
       return maxNumSectors * layer + offset;
     }
 
     //=============================================================================
     // -- Helper for non-trivial position calculation
     //=============================================================================
-    simd::int_v position( const simd::int_v positions, const int maxNumSectors, const int layer ) {
+    [[maybe_unused]] simd::int_v position( const simd::int_v positions, const int maxNumSectors, const int layer ) {
       return positions - maxNumSectors * layer;
     }