explicit exception chaining for spacy tasks

[sp1thas]

Summary

Adds explicit exception chaining so that exception stack traces are a bit easier to comprehend. See #3306 for a lot more detail and background discussion on this.

Thanks for your time and consideration!

note: Issue body is copied from #3320, created by @jameslamb.

Changes

Uses explicit exception chaining like raise RuntimeError("whatever") from exc in all the places in src/prefect/tasks/spacy/* that are missing it.

You can confirm that they were all caught by running the following from the root of the repo:

python -m pylint src/prefect/tasks/spacy --disable=all --enable=W0707

Importance

This pull request will make some of prefect's stack traces a bit easier to understand, to improve the user experience in debugging.

Checklist

This PR:

• adds new tests (if appropriate)
• adds a change file in the changes/ directory (if appropriate)
• updates docstrings for any new functions or function arguments, including docs/outline.toml for API reference docs (if appropriate)

[codecov]

Codecov Report

Merging #3479 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

[jcrist]

Thanks!