Dead keys are not reported as being pressed on linux in the new input system.

Repro:
1. Download Linux_Build_x64.zip and extract
2. Open a terminal and run: setxkbmap -layout us -variant intl (To switch back: setxkbmap -layout us)
3. Run Test.x86_64
4. Press any dead key like: `
5. Observe the key is not reported.

If you boot into windows and download/try Windows_Build_x64 with the us international keyboard you will see that dead keys are reported.

Forum thread:
https://forum.unity.com/threads/dead-keys-like-circumflex-azerty-doesnt-work.625951/

GitHub:
https://github.com/Unity-Technologies/InputSystem/issues/409