ci: Install libzstd-dev, required to compile with recent libelf-dev

Recent versions of libelf-dev also require libzstd-dev for compiling
bpftool. Make sure the library is installed on the runner.

Signed-off-by: Quentin Monnet <[email protected]>

Author: qmonnet

.github/workflows/build.yaml

@@ -36,7 +36,7 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y \
-              libbfd-dev libcap-dev libelf-dev libiberty-dev python3-docutils
+              libbfd-dev libcap-dev libelf-dev libzstd-dev libiberty-dev python3-docutils
           # clang/LLVM are already installed, but we're missing some aliases.
           CLANG_VERSION="$(echo '__clang_major__' | clang -E - | tail -n 1)"
           sudo update-alternatives \