AthenaMonitoring: remove support for LWHists
LWHists
(light-weight histograms) are not thread-safe and not used anymore. Remove
support for them also in the legacy DQ monitoring framework (which is sadly still used for PhysVal).
LWHists
(light-weight histograms) are not thread-safe and not used anymore. Remove
support for them also in the legacy DQ monitoring framework (which is sadly still used for PhysVal).