Install scenefx from AUR in build workflow

Added steps to install scenefx from AUR in the build workflow.

.github/workflows/build.yml

@@ -66,9 +66,21 @@ jobs:
             seatd \
             mesa \
             wlroots0.19 \
-            scenefx0.4 \
             pkg-config
             
+      - name: Install scenefx from AUR
+        run: |
+          # Install scenefx from AUR since it's not in official repos
+          # Create a non-root user for makepkg (AUR requires non-root)
+          useradd -m -G wheel builder
+          echo "builder ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
+          
+          # Clone and build scenefx from AUR as builder user
+          cd /home/builder
+          su - builder -c "git clone https://aur.archlinux.org/scenefx0.4.git"
+          cd scenefx
+          su - builder -c "cd /home/builder/scenefx && makepkg -si --noconfirm"
+
       - name: Configure meson
         run: |
           # Download meson subprojects if needed