devcontainer: add ssh package

Author: zeriyoshi

.devcontainer/Dockerfile

@@ -3,7 +3,7 @@ FROM debian:bookworm
 RUN apt-get update \
  && DEBIAN_FRONTEND="noninteractive" apt-get install -y \
       "build-essential" "autoconf" "bison" "re2c" "pkg-config" "zlib1g-dev" "libsqlite3-dev" "libpq-dev" "locales" \
-      "valgrind" "llvm" "clang" "git" "gdb" \
+      "valgrind" "llvm" "clang" "gdb" "git" "ssh" \
  && locale-gen "en_US.UTF-8"
 
 ENV LANGUAGE ""