[Internal] Switch code formatter to Black

[renaudhartert-db]

What changes are proposed in this pull request?

This PR switches the code formatter from yapf to black.

The rationale is that we want a code formatter that (i) leaves as little space as possible for discussions around formatting personal preferences, and (ii) increases the likelihood of producing code that is consistently formatted across the python open-source ecosystem.

At this point in time, we believe that black does a better job than yapf and other alternatives to address these two problems.

How is this tested?

No additional tests.

NO_CHANGELOG=true

[github-actions]

If integration tests don't run automatically, an authorized user can run them manually by following the instructions below:

Trigger:
go/deco-tests-run/sdk-py

Inputs:

• PR number: 900
• Commit SHA: 0aab32ea73d42590ff8438a294d600275e2a6cba

Checks will be approved automatically on success.

[denik]

Why not ruff? It is compatible with black and comes with a lot of lint rules. Much faster as well.

[renaudhartert-db]

Why not ruff? It is compatible with black and comes with a lot of lint rules. Much faster as well.

Formatting speed and linting are not problems we're trying to address at this point in time. It is possible that we will converge toward Ruff once we're done experimenting and have identified the tools we want to rely on. For now, we believe that moving to Black is a strict improvement of the status quo, which is easy to undo if we have to.