Fixed memory leak in observation operator due to unclosed ncfiles.

! 2023-08, Arjo Segers

!   Replaced `where` constructs by loops after memory errors on some systems.

!

! 2023-11, Arjo Segers

!   Close files also in 'read' mode ...

!

!###############################################################################

!

#define TRACEBACK write (csol,'("in ",a," (",a,", line",i5,")")') rname, __FILE__, __LINE__; call csoErr

  subroutine NcFile_Done( self, status )

    use NetCDF  , only : NF90_Close

    use CSO_Comm, only : csoc

    ! --- in/out ---------------------------------

    ! switch:

    select case ( self%rwmode )

      ! read, open:

      case ( 'r', 'o' )

      ! open:

      case ( 'o' )

        ! open/close is managed externally,

        ! nothing to be done

      ! write:

      case ( 'w' )

      ! read, write:

      case ( 'r', 'w' )

        ! written on root...

        if ( csoc%root ) then