Fix Ubuntu 18.04 build

Dockerfile

@@ -203,12 +203,11 @@ Pin-Priority: -1" > /etc/apt/preferences.d/firefox-ppa && \
         debconf-kde-helper \
         colord-kde \
         desktop-file-utils \
-        dragonplayer \
-        elisa \
         filelight \
         gwenview \
         hspell \
         kaddressbook \
+        kaffeine \
         kate \
         kcalc \
         kcharselect \
@@ -235,7 +234,6 @@ Pin-Priority: -1" > /etc/apt/preferences.d/firefox-ppa && \
         kwalletmanager \
         okular \
         okular-extra-backends \
-        plasma-browser-integration \
         plasma-dataengines-addons \
         plasma-discover \
         plasma-runners-addons \
@@ -243,7 +241,6 @@ Pin-Priority: -1" > /etc/apt/preferences.d/firefox-ppa && \
         plasma-widgets-addons \
         plasma-workspace-wallpapers \
         qtvirtualkeyboard-plugin \
-        software-properties-qt \
         sonnet-plugins \
         sweeper \
         systemsettings \

README.md

@@ -30,7 +30,7 @@ The username is `user` in both the container user account and the web authentica
 ```
 docker run --gpus 1 -it --tmpfs /dev/shm:rw -e TZ=UTC -e SIZEW=1920 -e SIZEH=1080 -e REFRESH=60 -e DPI=96 -e CDEPTH=24 -e VIDEO_PORT=DFP -e PASSWD=mypasswd -e WEBRTC_ENCODER=nvh264enc -e BASIC_AUTH_PASSWORD=mypasswd -p 8080:8080 ghcr.io/selkies-project/nvidia-glx-desktop:latest
 ```
-> NOTES: The container tags available are `latest` and `20.04` for Ubuntu 20.04 and `18.04` for Ubuntu 18.04. Replace all instances of `mypasswd` with your desired password. `BASIC_AUTH_PASSWORD` will default to `PASSWD` if unspecified. The container must not be run in privileged mode.
+> NOTES: The container tags available are `latest` and `22.04` for Ubuntu 22.04, `20.04` for Ubuntu 20.04, and `18.04` for Ubuntu 18.04. Replace all instances of `mypasswd` with your desired password. `BASIC_AUTH_PASSWORD` will default to `PASSWD` if unspecified. The container must not be run in privileged mode.
 
 Change `WEBRTC_ENCODER` to `x264enc`, `vp8enc`, or `vp9enc` when using the selkies-gstreamer interface if your GPU does not support `H.264 (AVCHD)` under the `NVENC - Encoding` section in NVIDIA's [Video Encode and Decode GPU Support Matrix](https://developer.nvidia.com/video-encode-and-decode-gpu-support-matrix-new).
 
@@ -53,7 +53,7 @@ kubectl create secret generic my-pass --from-literal=my-pass=YOUR_PASSWORD
 ```bash
 kubectl create -f xgl.yml
 ```
-> NOTES: The container tags available are `latest` and `20.04` for Ubuntu 20.04 and `18.04` for Ubuntu 18.04. `BASIC_AUTH_PASSWORD` will default to `PASSWD` if unspecified.
+> NOTES: The container tags available are `latest` and `22.04` for Ubuntu 22.04, `20.04` for Ubuntu 20.04, and `18.04` for Ubuntu 18.04. `BASIC_AUTH_PASSWORD` will default to `PASSWD` if unspecified.
 
 Change `WEBRTC_ENCODER` to `x264enc`, `vp8enc`, or `vp9enc` when using the selkies-gstreamer WebRTC interface if your GPU does not support `H.264 (AVCHD)` under the `NVENC - Encoding` section in NVIDIA's [Video Encode and Decode GPU Support Matrix](https://developer.nvidia.com/video-encode-and-decode-gpu-support-matrix-new).