Log Message:
Update cups-filters to 1.28.7

NEWS - OpenPrinting CUPS Filters v1.28.7 - 2021-01-07
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CHANGES IN V1.28.7

- driverless: Removed the support quality check from Pull
  request #235 as it takes significant time for each printer
  being listed, making cups-driverd (`lpinfo -m`) timing out
  when there are many printers (OpenPrinting CUPS issue #65).
- libcupsfilters: In the PPD generator give priority to Apple
  Raster against PDF (Issue #331).
- libcupsfilters: Added NULL check when removing ".Borderless"
  suffixes from page size names (Issue #314, Pull request
  #328).
- libcupsfilters: In the cupsRasterParseIPPOptions() map the
  color spaces the same way as in the PPD generator (Issue
  #326, Pull request #327).
- libcupsfilters: Fixed addition of grayscale mode in
  generated PPD files, to avoid duplicate entries
  (OpenPrinting CUPS issue #59).