libviprs 0.6.1

Fixed

• The Miri filesystem-test inventory lists the renamed pdfium dependency tests again (issue #1207).
• pdf_info sizes a page by its CropBox, like the render (issue #1209).
  get_page_dimensions read the MediaBox only, so for a page with a CropBox
  pdf info, plan and any buffer sized from pdf_info described a canvas
  that render_page_pdfium, viprs pdf extract --dpi and libvips
  pdfload[dpi=N] never produced (the A3 CropBox sheet is 3758x5127 at 300
  dpi from info and 3508x4961 from the render). It now reports the CropBox
  clipped to the MediaBox, both inherited through the page tree, then
  /Rotate. A missing, malformed (not four numbers), empty or disjoint CropBox
  falls back to the MediaBox, as in pdfium. The same walk fixes a MediaBox
  inherited from the /Pages node, which came back as 0x0. /UserUnit is
  still not applied: the render ignores it, and info matches the render. The
  arithmetic is f32, as pdfium's is, so a fractional box rounds to the same
  pixel. pdf_info on a cropped page reports a smaller size than before; see
  MIGRATION.md.