Sway 1.6 contains 231 changes, an assortment of new features, and a lot of bug fixes.

New features

• Input method editor (IME) improvements: better support for CJK IMEs, allow IMEs to work on desktop UIs (such as panels and lockscreens)
• Smoother interactive move/resize operations
• Allow Flatpak and snap applications to better integrate with the system via the xdg-foreign protocol
• Improved i3 compatibility for commands changing the window layout
• Add an option to hide the cursor when typing
• X11 clipboard reliability improvements

Note: Sway 1.6 may also require some of its dependencies to be updated, including wlroots (0.11 to 0.13), wayland (1.18 to 1.19) and wayland-protocols (1.20 to 1.21).

For convenience, I've posted all applicable tarball links below:

sway 1.6: https://github.com/swaywm/sway/releases/download/1.6/sway-1.6.tar.gz
wlroots 0.13: https://github.com/swaywm/wlroots/releases/download/0.13.0/wlroots-0.13.0.tar.gz
wayland 1.19: https://wayland.freedesktop.org/releases/wayland-1.19.0.tar.xz
wayland-protocols 1.21: https://wayland.freedesktop.org/releases/wayland-protocols-1.21.tar.xz