CFT-3212 - Feature/async

[kudj]

Add async HTTP client support

This PR adds an async variant of the HTTP client alongside the existing synchronous implementation.

What's new

• AsyncHttpClient: New async client built on httpx with the same interface as the sync client

  • Async/await support for non-blocking I/O operations
  • Built-in rate limiting via aiolimiter
  • Same retry logic, error handling, and parameter merging as the sync client

• Test coverage: Comprehensive async test suite with proper mock handling

• Documentation: Updated README with async examples and usage patterns

• Modernization:

  • Migrated from setup.py to pyproject.toml
  • Added uv for dependency management
  • Updated type hints to use modern syntax (dict | None instead of Optional[Dict])
  • Cleaned up imports and removed deprecated patterns

Breaking changes

None - the sync HttpClient API remains unchanged.

[Copilot]

Pull Request Overview

Adds an asynchronous HTTP client alongside the existing synchronous client, migrates packaging to pyproject.toml with uv-based workflows, modernizes type hints, and expands documentation and examples to cover async usage and CI changes.

• Introduces AsyncHttpClient with retry, backoff, optional rate limiting, and batch processing.
• Refactors sync client type hints / formatting and replaces setup.py with pyproject.toml plus updated CI workflows.
• Expands README and examples for async usage (some documentation inconsistencies introduced).

Reviewed Changes

Copilot reviewed 15 out of 18 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
tests/test_async.py	New test suite for AsyncHttpClient (params/header/auth/retry handling; lacks coverage for some new behaviors).
src/keboola/http_client/http.py	Type hint modernization, import adjustments, formatting; minor logic unchanged except stylistic edits.
src/keboola/http_client/async_client.py	New asynchronous client implementation with retries, backoff, rate limiting, and batch processing.
src/keboola/http_client/init.py	Exposes AsyncHttpClient at package root.
pyproject.toml	New project metadata replacing setup.py; changes project name and dependency management.
flake8.cfg	Updated lint configuration (ignore list and limits).
docs/examples/*	Added sync and async usage examples, including batch processing and rate limiting demos.
README.md	Extended documentation for async client and reorganized sections (contains inaccuracies).
.github/workflows/*.yml	Updated CI to use uv, add Python versions, automate version injection and publishing.
setup.py	Removed in favor of pyproject.toml.

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[Copilot]

Method contains no awaits and performs synchronous mutations only; consider making it a regular def to simplify usage (so callers need not await it) and align with the synchronous client's API.

Suggested change

	async def update_auth_header(self, updated_header: dict, overwrite: bool = False):
	def update_auth_header(self, updated_header: dict, overwrite: bool = False):

[Copilot]

Method contains no awaits and performs synchronous mutations only; consider making it a regular def to simplify usage (so callers need not await it) and align with the synchronous client's API.

[ZdenekSrotyr]

LGTM, tests look solid and everything reads well.

[soustruh]

LGTM, the updated client was thoroughly tested in many components already, the test coverage is also sufficient 👍