Dependencies: Add support for Python 3.10

[codecov[bot]]

Codecov Report

Base: 90.68% // Head: 90.72% // Increases project coverage by +0.04% :tada:

Coverage data is based on head (f52d8ba) compared to base (449f7e6). Patch has no changes to coverable lines.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #242 +/- ## ========================================== + Coverage 90.68% 90.72% +0.04% ========================================== Files 21 21 Lines 2960 2961 +1 ========================================== + Hits 2684 2686 +2 + Misses 276 275 -1 ``` | [Impacted Files](https://codecov.io/gh/aiidateam/plumpy/pull/242?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam) | Coverage Δ | | |---|---|---| | [src/plumpy/workchains.py](https://codecov.io/gh/aiidateam/plumpy/pull/242/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam#diff-c3JjL3BsdW1weS93b3JrY2hhaW5zLnB5) | `93.77% <0.00%> (+0.02%)` | :arrow_up: | | [src/plumpy/ports.py](https://codecov.io/gh/aiidateam/plumpy/pull/242/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam#diff-c3JjL3BsdW1weS9wb3J0cy5weQ==) | `93.32% <0.00%> (+0.31%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam)

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