[ci] Don't fail on apt update and revive clang-O3-O0

.circleci/config.yml

@@ -68,7 +68,8 @@ jobs:
       - image: multiarch/crossbuild
     steps:
       - checkout
-      - run: apt update && apt install -y ragel libfreetype6-dev libglib2.0-dev libcairo2-dev libicu-dev libgraphite2-dev python python-pip
+      - run: apt update || true
+      - run: apt install -y ragel libfreetype6-dev libglib2.0-dev libcairo2-dev libicu-dev libgraphite2-dev python python-pip
       - run: pip install fonttools
       - run: wget http://download.savannah.gnu.org/releases/freetype/freetype-2.9.tar.bz2 && tar xf freetype-2.9.tar.bz2 && cd freetype-2.9 && ./autogen.sh && ./configure && make -j4 && cd ..
       - run: CFLAGS="-O3" CXXFLAGS="-O3" CC=clang CXX=clang++ ./autogen.sh --with-freetype --with-glib --with-cairo --with-icu --with-graphite2