github actions: switch to llvm automated install script

Author: tyler569

.github/workflows/build.yml

@@ -11,14 +11,16 @@ jobs:
           fetch-depth: 0
       - name: Install OS dependancies
         run: |
-          sudo apt update
-          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          sudo add-apt-repository -y "deb https://apt.llvm.org/jammy/ llvm-toolchain-jammy main"
           sudo apt-get update
           sudo apt-get upgrade
-          sudo apt install git make cmake ninja-build ruby clang lld xorriso mtools qemu-system
+          sudo apt-get install git make cmake ninja-build ruby xorriso mtools qemu-system wget
+          wget https://apt.llvm.org/llvm.sh
+          chmod +x llvm.sh
+          sudo ./llvm.sh 18
       - name: build
-        run: make
+        run: |
+          cmake -Bbuild -GNinja -DCMAKE_C_COMPILER=clang-18 -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=toolchain/CMake/CMakeToolchain.txt
+          cmake --build build
       - name: Upload ISO
         uses: actions/upload-artifact@v2
         with: