Add LocalStack template for AWS service integration testing with:
- Docker-in-Docker configuration with registry mirroring
- Automatic LocalStack version management via .tool-versions
- AWS CLI and awslocal wrapper installation with readiness checks
- Comprehensive documentation with Go, Python, and Node.js examples

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)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

- Add $HOME/.local/bin to PATH after installing pipx so AWS CLI and
  awslocal are immediately available
- Set DEBIAN_FRONTEND=noninteractive to suppress debconf warnings
  during apt-get install

🤖 Generated with [Claude Code](https://claude.com/claude-code

)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Co-authored-by: GitLab Duo <gitlab-duo@gitlab.com>

feat(localstack): add Localstack integration test template

See merge request !1245

## [3.4.0](https://gitlab.com/gitlab-com/gl-infra/common-ci-tasks/-/compare/...) (2025-12-10)

### Features

* **localstack:** add integration test template ([a129a3dd](a129a3dd))

### Fixes

* **localstack:** ensure pipx bin directory is in PATH and suppress apt warnings ([44749ea0](44749ea0))