dataTableHeaderCellClassName function
Header cell className.
Carries no track: the track is the wrapper's job (see
dataTableTrackClassName), so alignment can be applied to a flexing column
as well as to a fixed one. It used to live here as a flex-1, which is why
alignEnd was silently ignored on every flexing column.
Implementation
String dataTableHeaderCellClassName() =>
'py-2 pr-3 text-xs font-medium uppercase tracking-wide text-fg-muted';