fix: repair the local source-code image build

[shreemaan-abhishek]

The CI for docker image built from local source code workflow has failed on every scheduled master run for over a week. Two separate problems in debian-dev/Dockerfile.local, one behind the other.

1. Debian 11 pool objects are gone

Both stages build on debian:bullseye-slim. The bullseye-security index is still published and still refreshed, but the .deb objects it points at have been removed from the mirrors:

curl -s http://deb.debian.org/debian-security/dists/bullseye-security/updates/main/binary-amd64/Packages.gz \
  | gunzip | awk '/^Package: sudo$/,/^$/' | grep -E '^(Version|Filename)'
# Version: 1.9.5p2-3+deb11u4
# Filename: pool/updates/main/s/sudo/sudo_1.9.5p2-3+deb11u4_amd64.deb

curl -o /dev/null -w '%{http_code}\n' -s \
  'http://deb.debian.org/debian-security/pool/updates/main/s/sudo/sudo_1.9.5p2-3%2bdeb11u4_amd64.deb'
# 404

apt-get update therefore succeeds and apt-get install fails with a 404 on ten packages, exiting 100 before any APISIX code is touched:

E: Failed to fetch .../sudo_1.9.5p2-3+deb11u4_amd64.deb  404  Not Found
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

This moves both stages to debian:bookworm-slim, which is what the production debian/Dockerfile already uses. These were the only two bullseye references left in the repo.

2. xz is missing, so the runtime tarball cannot be unpacked

Behind the apt failure sits a second one. make deps fetches the APISIX-Runtime as a .tar.xz, and neither debian:bullseye-slim nor debian:bookworm-slim ships xz:

tar (child): xz: Cannot exec: No such file or directory
tar (child): Error is not recoverable: exiting now
make: *** [Makefile:240: install-runtime] Error 2

xz-utils is added to the build stage. This is independent of the base image: the same failure is reachable on bullseye once the packages resolve, so fixing only the base image would leave the job red.

Verification

Both failures were reproduced against this tree and each fix confirmed by the build advancing past it: the apt step resolves on bookworm, and install-runtime completes with xz-utils present. The full image build is left to CI here.