Fix macos build (#5703)

* Update deps.sh

GitHub's virtual environment provides 7zip and llvm by default, so brew may fail to install them as another version is already installed

* Use || true to ignore brew installation errors

.ci/macos/deps.sh

@@ -3,5 +3,5 @@
 brew update
 brew unlink python@2 || true
 rm '/usr/local/bin/2to3' || true
-brew install qt5 sdl2 p7zip ccache ffmpeg llvm ninja
+brew install qt5 sdl2 p7zip ccache ffmpeg llvm ninja || true
 pip3 install macpack