actions: fix build script

.github/workflows/nightly.yml

@@ -15,17 +15,16 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
-      - name: Install build dependencies
+      - name: Install cross toolchain
+        uses: risonakamo/setup-x86_64-elf-gcc@v1
+
+      - name: Install userland build tools
         run: |
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             make \
-            gcc-x86-64-linux-gnu \
-            binutils-x86-64-linux-gnu \
             nasm \
             xorriso
-          sudo ln -sf /usr/bin/x86_64-linux-gnu-gcc /usr/local/bin/x86_64-elf-gcc
-          sudo ln -sf /usr/bin/x86_64-linux-gnu-ld /usr/local/bin/x86_64-elf-ld
 
       - name: Build ISO
         run: make -j4