infra: CI/CD pipelines (lint, test, release)

[kristopherjturner]

Overview

Implement CI/CD pipelines for linting, testing, and releasing the loadtools framework. Pipelines ensure code quality gates are enforced on every PR and that releases produce versioned artifacts.

Scope

• GitHub Actions workflow: lint (flake8/ruff + shellcheck + PSScriptAnalyzer)
• GitHub Actions workflow: unit tests (pytest with coverage report)
• GitHub Actions workflow: integration tests (against a test Azure Local cluster, if available)
• Release pipeline: semantic versioning, CHANGELOG generation, GitHub Release artifact
• Dependabot configuration for dependency updates
• Release Please integration for automated release notes

Acceptance Criteria

• Lint and unit test workflows trigger on every PR
• Coverage report posted as PR comment
• Release workflow triggers on merge to main via Release Please
• GitHub Release includes versioned artifact (ZIP of src/ and config/)
• All pipeline configs in .github/workflows/

Dependencies

• Parent Epic: [Epic] Load Testing Toolkit Full Build-Out #8
• IaC maturity tracking: Track IaC tool maturity status across all repos (Built / Tested / Released) azurelocal-toolkit#5

[kristopherjturner]

Related to AzureLocal/azurelocal-toolkit#16 (TKT-6) — Research: Azure Deployment Stacks for ARM/Bicep Deployments. Implementation of this issue should account for deployment stack adoption across all repos.