ci: Use clang-19 from apt.llvm.org

ci/test/00_setup_env_native_fuzz.sh

@@ -8,7 +8,8 @@ export LC_ALL=C.UTF-8
 
 export CI_IMAGE_NAME_TAG="docker.io/ubuntu:24.04"
 export CONTAINER_NAME=ci_native_fuzz
-export PACKAGES="clang-18 llvm-18 libclang-rt-18-dev libevent-dev libboost-dev libsqlite3-dev"
+export APT_LLVM_V="19"
+export PACKAGES="clang-${APT_LLVM_V} llvm-${APT_LLVM_V} libclang-rt-${APT_LLVM_V}-dev libevent-dev libboost-dev libsqlite3-dev"
 export NO_DEPENDS=1
 export RUN_UNIT_TESTS=false
 export RUN_FUNCTIONAL_TESTS=false
@@ -18,9 +19,9 @@ export CI_CONTAINER_CAP="--cap-add SYS_PTRACE"  # If run with (ASan + LSan), the
 export BITCOIN_CONFIG="\
  -DBUILD_FOR_FUZZING=ON \
  -DSANITIZERS=fuzzer,address,undefined,float-divide-by-zero,integer \
- -DCMAKE_C_COMPILER=clang-18 \
- -DCMAKE_CXX_COMPILER=clang++-18 \
+ -DCMAKE_C_COMPILER=clang-${APT_LLVM_V} \
+ -DCMAKE_CXX_COMPILER=clang++-${APT_LLVM_V} \
  -DCMAKE_C_FLAGS='-ftrivial-auto-var-init=pattern' \
  -DCMAKE_CXX_FLAGS='-ftrivial-auto-var-init=pattern' \
 "
-export LLVM_SYMBOLIZER_PATH="/usr/bin/llvm-symbolizer-18"
+export LLVM_SYMBOLIZER_PATH="/usr/bin/llvm-symbolizer-${APT_LLVM_V}"