Regenerate expected fixtures for libvips v8.17.0

[kleisauke]

Regenerate extract.tiff to avoid an test failure due to PR libvips/libvips#4313.

$ curl -LO https://github.com/lovell/sharp/raw/v0.34.2/test/fixtures/expected/extract.tiff
$ vips copy extract.tiff[fail-on=warning] x.jpg 

(vips:22733): tiff2vips-WARNING **: 14:54:38.286: The JPEG strip/tile is encoded with progressive mode, which is normally not legal for JPEG-in-TIFF.
libtiff should be able to decode it, but it might cause compatibility issues with other readers

(vips:22733): VIPS-WARNING **: 14:54:38.287: error in tile 0 x 0

[lovell]

Thanks Kleis, your suggested change for the TIFF extraction test looks good. For the composite tests, does forcing a higher PNG bitdepth for both the expected and actual fixtures via something like .toColourspace('rgb16') help?

[kleisauke]

For the composite tests, does forcing a higher PNG bitdepth for both the expected and actual fixtures via something like .toColourspace('rgb16') help?

This didn't help. I've opened PR libvips/libvips#4547 to avoid that change.

[lovell]

Thank you Kleis.