CI, README: Update for mutter bump

Requires ubuntu-22.04 to run CI, see elementary/docker issue 25.

.github/workflows/main.yml

@@ -5,17 +5,17 @@ on: [push, pull_request]
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     container:
-      image: elementary/docker:unstable
+      image: elementary/docker:next-unstable
 
     steps:
     - uses: actions/checkout@v2
     - name: Install Dependencies
       run: |
         apt update
-        apt install -y gettext gnome-settings-daemon-dev gsettings-desktop-schemas-dev libbamf3-dev libcanberra-dev libcanberra-gtk3-dev libclutter-1.0-dev libgee-0.8-dev libglib2.0-dev libgnome-desktop-3-dev libgranite-dev libgtk-3-dev libmutter-6-dev libplank-dev libxml2-utils libgexiv2-dev meson valac valadoc
+        apt install -y gettext gnome-settings-daemon-dev gsettings-desktop-schemas-dev libbamf3-dev libcanberra-dev libcanberra-gtk3-dev libclutter-1.0-dev libgee-0.8-dev libglib2.0-dev libgnome-desktop-3-dev libgranite-dev libgtk-3-dev libmutter-10-dev libplank-dev libxml2-utils libgexiv2-dev meson valac valadoc
     - name: Build
       env:
         DESTDIR: out

README.md

@@ -19,9 +19,9 @@ You'll need the following dependencies:
 * libgnome-desktop-3-dev
 * libgranite-dev (>= 5.4.0)
 * libgtk-3-dev (>= 3.10.0)
-* libmutter-6-dev (>= 3.35.1) | libmutter-dev (>= 3.18.3)
+* libmutter-10-dev (>= 42.0) | libmutter-dev (>= 3.18.3)
 * libxml2-utils
-* valac (>= 0.28.0)
+* valac (>= 0.50.0)
 
 Run `meson build` to configure the build environment. Change to the build directory and run `ninja` to build