Update wlroots in CI builds to 0.8.1

.builds/alpine.yml

@@ -17,10 +17,8 @@ tasks:
   # version, instead of master, to avoid any breaking changes in wlroots.
   - wlroots: |
       cd wlroots
-      # We'd like to build against the latest release (0.6.0), but that doesn't compile
-      # against libinput 1.14. This commit introduces support for that version.
-      git checkout 94f65e354d09ded037e6ba724dc3eeed6d63778f
-      meson --prefix=/usr build -Drootston=false -Dexamples=false
+      git checkout 0.8.1
+      meson --prefix=/usr build -Dexamples=false
       ninja -C build
       sudo ninja -C build install
   - build: |