fix: migrate to Policyfile

[damacus]

Summary

• Replace Berkshelf dependency management with Policyfile/Policyfile.lock.
• Switch ChefSpec and Kitchen to Policyfile support while preserving named test run-list semantics.
• Remove stale Berkshelf setup/ignore references and fix existing lint blockers in CI/docs.

Validation

• chef install Policyfile.rb
• chef update Policyfile.rb
• cookstyle
• env GEM_HOME=/opt/chef-workstation/embedded/lib/ruby/gems/3.1.0 GEM_PATH=/opt/chef-workstation/embedded/lib/ruby/gems/3.1.0 /opt/chef-workstation/embedded/bin/rspec --format documentation
• markdownlint-cli2 "**/*.md" "!vendor" "!.venv"
• yamllint .github .markdownlint-cli2.yaml .overcommit.yml .rubocop.yml kitchen.dokken.yml kitchen.exec.yml kitchen.global.yml kitchen.yml test/integration
• actionlint -no-color -oneline
• git diff --check
• kitchen list
• env -u DOCKER_HOST kitchen diagnose package-ubuntu-2404
• env -u DOCKER_HOST kitchen test package-ubuntu-2404 --destroy=always

[github-actions]

Slowest examples

Top 10 slowest examples (1.06 seconds, 45.45% of total time)

Example	Description	Time in seconds
spec/unit/recipes/cache_spec.rb:45	haproxy_cache create a cache, frontend and backend and verify config is created properly is expected to render file "/etc/haproxy/haproxy.cfg"	0.1386
spec/unit/recipes/install_spec.rb:73	haproxy_install compile HAProxy on Amazon Linux (uses PCRE) is expected not to install package "pcre2-devel"	0.13765
spec/unit/recipes/defaults_spec.rb:26	haproxy_config_defaults create a cache, frontend and backend and verify config is created properly is expected to render file "/etc/haproxy/haproxy.cfg"	0.13633
spec/unit/recipes/install_spec.rb:30	haproxy_install compile HAProxy on Ubuntu is expected to install package "["libpcre3-dev", "libssl-dev", "zlib1g-dev", "libsystemd-dev"]"	0.12756
spec/unit/recipes/mailer_spec.rb:48	haproxy_mailer create a mailer, frontend and backend and verify config is created properly is expected to render file "/etc/haproxy/haproxy.cfg"	0.09188
spec/unit/recipes/listen_spec.rb:105	haproxy_listen extra options http-request rule should be placed before use_backend rule is expected to render file "/etc/haproxy/haproxy.cfg"	0.08905
spec/unit/recipes/fastcgi_spec.rb:63	haproxy_fastcgi create a fastcgi resource, frontend and backend and verify config is created properly is expected to render file "/etc/haproxy/haproxy.cfg"	0.08766
spec/unit/recipes/listen_spec.rb:61	haproxy_listen option parameter with array of options is expected to render file "/etc/haproxy/haproxy.cfg"	0.08704
spec/unit/recipes/peer_spec.rb:45	haproxy_peer create a peers section, frontend and backend and verify config is created properly is expected to render file "/etc/haproxy/haproxy.cfg"	0.0863
spec/unit/recipes/listen_spec.rb:106	haproxy_listen extra options http-request rule should be placed before use_backend rule is expected not to render file "/etc/haproxy/haproxy.cfg" with content /use_backend admin0 if path_beg /admin0.*http-request add-header Test Value/m	0.08627