GitHub Actions/iOS: shift to using a pre-packaged Qt installation

Since the official Qt binaries can no longer be installed without disclosing
credentials (well, sure, that could be done through secrets), I decided that
we should go back to packaging just the part of the iOS Qt SDK that we need.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

.github/workflows/ios.yml

@@ -18,29 +18,16 @@ jobs:
     - name: set our Qt build
       run: |
         env
-        curl -L --output qt-opensource-mac-x64-5.13.1.dmg https://download.qt.io/archive/qt/5.13/5.13.1/qt-opensource-mac-x64-5.13.1.dmg
-        df -h
-        mkdir -p mnt
-        sudo hdiutil attach -mountroot $PWD/mnt -noverify -noautoopen -verbose qt-opensource-mac-x64-5.13.1.dmg
-        df -h
-        ls -l mnt
-        find mnt
-        ./mnt/qt-opensource-mac-x64-5.13.1/qt-opensource-mac-x64-5.13.1.app/Contents/MacOS/qt-opensource-mac-x64-5.13.1 --platform minimal --script packaging/ios/qt-installer-noninteractive.qs --no-force-installations
-        df -h
+        curl -L --output Qt-5.14.1-ios.tar.xz https://f002.backblazeb2.com/file/Subsurface-Travis/Qt-5.14.1-ios.tar.xz
+        mkdir -p $HOME/Qt
+        xzcat Qt-5.14.1-ios.tar.xz | tar -x -C $HOME/Qt -f -
     - name: build Subsurface-mobile for iOS
       run: |
-        ls -l $HOME $HOME/Qt
         cd packaging/ios
         ln -s $HOME/Qt Qt
-        pushd Qt
-        ls -l
-        popd
         echo "build dependencies"
         bash -x build.sh -simulator
         echo "Subsurface-mobile for iOS"
         cd build-Subsurface-mobile-*for_iOS-Release
         sed -i.bak 's/-Wall/-Wno-everything/' Makefile # make the build far less verbose
         make -j2
-
-
-