ci: Use clang-20 for sanitizer tasks

ci/test/00_setup_env_native_fuzz.sh

@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export CI_IMAGE_NAME_TAG="docker.io/ubuntu:24.04"
 export CONTAINER_NAME=ci_native_fuzz
-export APT_LLVM_V="19"
+export APT_LLVM_V="20"
 export PACKAGES="clang-${APT_LLVM_V} llvm-${APT_LLVM_V} libclang-rt-${APT_LLVM_V}-dev libevent-dev libboost-dev libsqlite3-dev"
 export NO_DEPENDS=1
 export RUN_UNIT_TESTS=false