v0.28.0

What's Changed

• Add libvips observablity functions #150
• Allow returning the mutated image from mutate callback by @kipcole9 in #152
• Update Github CI & switch to nix based CI for macos in #155
• Add write_area_to_binary and get_pixel in #157
• Make undocumented functions Image.fetch_range, Image.log_warn private in #157
• Raise Image.Error instead of RuntimeError wherever appropriate in #157

Full Changelog: v0.27.0...v0.28.0