[ci/ubsan] Disable enum sanitization

Behdad apparently not interested on them
diff --git a/.circleci/config.yml b/.circleci/config.yml
index 1cf4bc8..0eb35f8 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -168,7 +168,7 @@
       - run: apt update || true
       - run: apt install -y clang lld binutils libtool autoconf automake make pkg-config ragel libfreetype6-dev libglib2.0-dev libcairo2-dev libicu-dev libgraphite2-dev python python-pip
       - run: pip install fonttools
-      - run: CPPFLAGS="-fsanitize=undefined" LDFLAGS="-fsanitize=undefined -O1 -g -fno-omit-frame-pointer" CFLAGS="-fsanitize=undefined -O1 -g -fno-omit-frame-pointer" CXXFLAGS="-fsanitize=undefined -O1 -g -fno-omit-frame-pointer" LD=ld.lld CC=clang CXX=clang++ ./autogen.sh --with-freetype --with-glib --with-cairo --with-icu --with-graphite2
+      - run: CPPFLAGS="-fsanitize=undefined -fno-sanitize=enum" LDFLAGS="-fsanitize=undefined -fno-sanitize=enum -O1 -g -fno-omit-frame-pointer" CFLAGS="-fsanitize=undefined -fno-sanitize=enum -O1 -g -fno-omit-frame-pointer" CXXFLAGS="-fsanitize=undefined -O1 -g -fno-omit-frame-pointer" LD=ld.lld CC=clang CXX=clang++ ./autogen.sh --with-freetype --with-glib --with-cairo --with-icu --with-graphite2
       - run: make -j32
       - run: make check || .ci/fail.sh | asan_symbolize | c++filt