Taskcluster-taskgraph

Fixed

- Relaxed PyYaml dependency constraint to work around a PyYaml issue

Fixed

- Reverted memoize on `load_yaml` utility which causes issues with parallel generations
- Added line to log command used to invoke `run-task`

Added

- Support for overriding the default task deadline in `ci/config.yml`

Added

- Support for Mercurial 6.0+ in `robustcheckout` script
- Added an `all` group for the `from_deps` transforms
- Added support for the `purgeCaches` feature of `generic-worker`

Fixed

- Added missing line feed to Python version log in `run-task` script
- Return null revision when no common ancestor found in `repo.find_latest_common_revision`
- Added `--force` flag when updating Git submodules in `run-task` script
- Fix ImportError with old versions of Python (fail on version check instead)

Fixed

- Regression in add-new-jobs and retrigger actions, introduced in 5.1.0.

Changed

- Replaced 'attrs' with 'dataclasses'

Fixed

- Disallow extraneous keys in the `from-deps` config
- `run-task` now fetches tags when necessary after cloning repo

Added

- New `from-deps.unique-kinds` key to allow depending on multiple tasks of a kind
- New `get_dependencies` and `get_primary_dependency` functions in `taskgraph.util.dependencies`
- `run-task` now logs the Python version it was invoked with