Simplify juce-au handling

Signed-off-by: falkTX <falktx@falktx.com>

.github/workflows/build.yml

@@ -215,8 +215,6 @@ jobs:
         run: |
           export PATH="/usr/local/opt/ccache/libexec:${PATH}"
           source deps/PawPaw/local.env macos-${{ matrix.target }}
-          git clone --depth=1 -b v6.1.6 https://github.com/DISTRHO/JUCE.git jucewrapper/JUCE
-          ${{ matrix.target == 'intel' }} && sed -i -e 's/kAudioUnitProperty_SupportsMPE/kAudioUnitProperty_ignore_SupportsMPE/' jucewrapper/JUCE/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.h
           mkdir -p jucewrapper/build
           pushd jucewrapper/build; cmake -DCMAKE_BUILD_TYPE=Release .. && make VERBOSE=1 -j $(sysctl -n hw.logicalcpu); popd
           mv jucewrapper/build/*_artefacts/Release/AU/*.component bin/

jucewrapper/CMakeLists.txt

@@ -1,7 +1,13 @@
 cmake_minimum_required(VERSION 3.15)
 project(Cardinal VERSION 23.04)
 
-add_subdirectory(JUCE)
+include(FetchContent)
+FetchContent_Declare(JUCE
+  GIT_REPOSITORY https://github.com/DISTRHO/JUCE.git
+  GIT_TAG v6.1.6
+  GIT_SHALLOW TRUE
+)
+FetchContent_MakeAvailable(JUCE)
 
 # Config