Use clang-18 for building binary

For some reason, clang-16 is not available anymore on debian testing.
Switching to clang 18 (available in both ubuntu 24.04 github runner
and debian testing) unblocks the build

Dockerfile

@@ -8,7 +8,7 @@ RUN cross_debian_arch=$(uname -m | sed -e 's/aarch64/amd64/'  -e 's/x86_64/arm64
     cross_pkg_arch=$(uname -m | sed -e 's/aarch64/x86-64/' -e 's/x86_64/aarch64/'); \
     apt-get update -y && \
     apt-get dist-upgrade -y && \
-    apt-get install -y wget make git clang-16 unzip libc6-dev g++ gcc pkgconf \
+    apt-get install -y wget make git clang-18 unzip libc6-dev g++ gcc pkgconf \
         gcc-${cross_pkg_arch}-linux-gnu libc6-${cross_debian_arch}-cross && \
     apt-get clean autoclean && \
     apt-get autoremove --yes

support/ebpf/Makefile

@@ -1,7 +1,7 @@
 SHELL ?= bash
-BPF_CLANG ?= clang-16
-BPF_LINK ?= llvm-link-16
-LLC ?= llc-16
+BPF_CLANG ?= clang-18
+BPF_LINK ?= llvm-link-18
+LLC ?= llc-18
 
 DEBUG_FLAGS = -DOPTI_DEBUG -g