Changes since 8.10.1:

• update magicksave/load profile handling [kelilevi]
• better demand hint rules [kaas3000]
• fix tiff thumbnail from buffer and source [vansante]
• in jpegsave, don't set JFIF resolution if we set EXIF resolution
• bump minimum libheif version to 1.3 [lovell]
• dzsave in iiif mode could set info.json dimensions off by one [Linden6]
• pdfload allows dpi and scale to both be set [le0daniel]
• allow gaussblur sigma zero, meaning no blur
• better heif signature detection [lovell]
• fix vips_fractsurf() typo [kleisauke]
• better heif EOF detection [lovell]
• fix gir build with g-o-i 1.66+ [László]
• improve seek behaviour on pipes
• add "speed" param to heifsave [lovell]
• fix regression in C path for dilate / erode [kleisauke]
• fix build with libheif save but no load [estepnv]