make(1): inline Lst_ForEachUntil in Compat_Make

This avoids the extra local function and a few conversions to void
pointers, to gain additional type safety.

The code in Compat_RunCommand does not modify gn->commands structurally,
therefore it does not need the extra complexity of Lst_ForEachUntil.  It
does have access to a list node to exactly this list.  This list node is
only used to set the command to NULL after processing it, not for
removing the node from the list.

(rillig)