Run under Wayland

Directly running under Wayland fixes blurriness when using fractional scaling. The same applies to other Mozilla applications such as Thunderbird.

flatpak override --env=MOZ_USE_WAYLAND=1 org.mozilla.firefox

Make the change permanently in the desktop file:

--- /usr/share/applications/firefox.desktop 2022-11-14 17:26:49.000000000 +0000
+++ /home/lukecarrier/.local/share/applications/firefox.desktop 2022-10-30 19:51:57.722589670 +0000
@@ -112,7 +112,7 @@
 Keywords[vi]=Internet;WWW;Browser;Web;Explorer;Trình duyệt;Trang web
 Keywords[zh_CN]=Internet;WWW;Browser;Web;Explorer;网页;浏览;上网;火狐;Firefox;ff;互联网;网站;
 Keywords[zh_TW]=Internet;WWW;Browser;Web;Explorer;網際網路;網路;瀏覽器;上網;網頁;火狐
-Exec=/usr/lib/firefox/firefox %u
+Exec=/usr/bin/env MOZ_ENABLE_WAYLAND=1 /usr/lib/firefox/firefox %u
 Icon=firefox
 Terminal=false
 X-MultipleArgs=false
@@ -229,7 +229,7 @@
 Name[xh]=Ifestile entsha
 Name[zh_CN]=新建窗口
 Name[zh_TW]=開新視窗
-Exec=/usr/lib/firefox/firefox --new-window %u
+Exec=/usr/bin/env MOZ_ENABLE_WAYLAND=1 /usr/lib/firefox/firefox --new-window %u

 [Desktop Action new-private-window]
 Name=New Private Window
@@ -337,4 +337,4 @@
 Name[xh]=Ifestile yangasese entsha
 Name[zh_CN]=新建隐私浏览窗口
 Name[zh_TW]=新增隱私視窗
-Exec=/usr/lib/firefox/firefox --private-window %u
+Exec=/usr/bin/env MOZ_ENABLE_WAYLAND=1 /usr/lib/firefox/firefox --private-window %u