chore(deps): update dependency pip-tools to v6.8.0 (#226)
chore(deps): update dependency pip-tools to v6.8.0 (#226)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [pip-tools](https://togithub.com/jazzband/pip-tools) | `==6.4.0` -> `==6.8.0` | [![age](https://badges.renovateapi.com/packages/pypi/pip-tools/6.8.0/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/pypi/pip-tools/6.8.0/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/pypi/pip-tools/6.8.0/compatibility-slim/6.4.0)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/pypi/pip-tools/6.8.0/confidence-slim/6.4.0)](https://docs.renovatebot.com/merge-confidence/) |

---

### Release Notes

<details>
<summary>jazzband/pip-tools</summary>

### [`v6.8.0`](https://togithub.com/jazzband/pip-tools/blob/HEAD/CHANGELOG.md#&#8203;680-2022-06-30)

[Compare Source](https://togithub.com/jazzband/pip-tools/compare/6.7.0...6.8.0)

Features:

-   Add support for pip's 2020 dependency resolver. Use
    `pip-compile --resolver backtracking` to enable new resolver
    ([#&#8203;1539](https://togithub.com/jazzband/pip-tools/pull/1539)). Thanks [@&#8203;atugushev](https://togithub.com/atugushev)

### [`v6.7.0`](https://togithub.com/jazzband/pip-tools/blob/HEAD/CHANGELOG.md#&#8203;670-2022-06-27)

[Compare Source](https://togithub.com/jazzband/pip-tools/compare/6.6.2...6.7.0)

Features:

-   Support for the `importlib.metadata` metadata implementation
    ([#&#8203;1632](https://togithub.com/jazzband/pip-tools/pull/1632)). Thanks [@&#8203;richafrank](https://togithub.com/richafrank)

Bug Fixes:

-   Instantiate a new accumulator `InstallRequirement` for `combine_install_requirements`
    output ([#&#8203;1519](https://togithub.com/jazzband/pip-tools/pull/1519)). Thanks [@&#8203;richafrank](https://togithub.com/richafrank)

Other Changes:

-   Replace direct usage of the `pep517` module with the `build` module, for loading
    project metadata ([#&#8203;1629](https://togithub.com/jazzband/pip-tools/pull/1629)). Thanks
    [@&#8203;AndydeCleyre](https://togithub.com/AndydeCleyre)

### [`v6.6.2`](https://togithub.com/jazzband/pip-tools/blob/HEAD/CHANGELOG.md#&#8203;662-2022-05-23)

[Compare Source](https://togithub.com/jazzband/pip-tools/compare/6.6.1...6.6.2)

Bug Fixes:

-   Update `PyPIRepository::resolve_reqs()` for pip>=22.1.1
    ([#&#8203;1624](https://togithub.com/jazzband/pip-tools/pull/1624)). Thanks [@&#8203;m000](https://togithub.com/m000)

### [`v6.6.1`](https://togithub.com/jazzband/pip-tools/blob/HEAD/CHANGELOG.md#&#8203;661-2022-05-13)

[Compare Source](https://togithub.com/jazzband/pip-tools/compare/6.6.0...6.6.1)

Bug Fixes:

-   Fix support for pip>=22.1 ([#&#8203;1618](https://togithub.com/jazzband/pip-tools/pull/1618)).
    Thanks [@&#8203;wizpig64](https://togithub.com/wizpig64)

### [`v6.6.0`](https://togithub.com/jazzband/pip-tools/blob/HEAD/CHANGELOG.md#&#8203;660-2022-04-06)

[Compare Source](https://togithub.com/jazzband/pip-tools/compare/6.5.1...6.6.0)

Features:

-   Add support for pip>=22.1 ([#&#8203;1607](https://togithub.com/jazzband/pip-tools/pull/1607)).
    Thanks [@&#8203;atugushev](https://togithub.com/atugushev)

Bug Fixes:

-   Ensure `pip-compile --dry-run --quiet` still shows what would be done, while omitting
    the dry run message ([#&#8203;1592](https://togithub.com/jazzband/pip-tools/pull/1592)). Thanks
    [@&#8203;AndydeCleyre](https://togithub.com/AndydeCleyre)
-   Fix `--generate-hashes` when hashes are computed from files
    ([#&#8203;1540](https://togithub.com/jazzband/pip-tools/pull/1540)). Thanks [@&#8203;RazerM](https://togithub.com/RazerM)

### [`v6.5.1`](https://togithub.com/jazzband/pip-tools/blob/HEAD/CHANGELOG.md#&#8203;651-2022-02-08)

[Compare Source](https://togithub.com/jazzband/pip-tools/compare/6.5.0...6.5.1)

Bug Fixes:

-   Ensure canonicalized requirement names are used as keys, to prevent unnecessary
    reinstallations during sync
    ([#&#8203;1572](https://togithub.com/jazzband/pip-tools/pull/1572)). Thanks [@&#8203;AndydeCleyre](https://togithub.com/AndydeCleyre)

### [`v6.5.0`](https://togithub.com/jazzband/pip-tools/blob/HEAD/CHANGELOG.md#&#8203;650-2022-02-04)

[Compare Source](https://togithub.com/jazzband/pip-tools/compare/6.4.0...6.5.0)

Features:

-   Add support for pip>=22.0, drop support for Python 3.6
    ([#&#8203;1567](https://togithub.com/jazzband/pip-tools/pull/1567)). Thanks [@&#8203;di](https://togithub.com/di)
-   Test on Python 3.11 ([#&#8203;1527](https://togithub.com/jazzband/pip-tools/pull/1527)). Thanks
    [@&#8203;hugovk](https://togithub.com/hugovk)

Other Changes:

-   Minor doc edits ([#&#8203;1445](https://togithub.com/jazzband/pip-tools/pull/1445)). Thanks
    [@&#8203;ssiano](https://togithub.com/ssiano)

</details>

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