meta: v1.9.6

Refactor cleanup method in AcceleratedCryptographicHash to be const

- Updated the cleanup() method to be a const method, ensuring it does not modify the state of the object.
- Made the status member variable mutable to allow modification within const methods.

Update 1.9.4 changelog

README: Update build instructions

Linux: rename .desktop file to match DBus name

Fixes #785

Add PL translation to CMakeLists.txt

Disable update check for rpi-os release

On rpi-os updates will be handled by apt, so directing the user to the
website is unhelpful.

Merge pull request #728 from tdewey-rpi/release/1.8.3

meta: v1.8.3

Release 1.8.1

Bump version number