pre-commit hook formats yaml

Rationale

In addition to bumping versions (desired), bad formatting (undesired) results.

a .pre-commit-config.yaml before...

repos:
  - repo: 'https://gitlab.com/vojko.pribudic.foss/pre-commit-update'
    rev: v0.3.1
    hooks:
      - id: pre-commit-update

... & after poetry run pre-commit run pre-commit-update (equivalent to pre-commit run pre-commit-update)

repos:
-   repo: 'https://gitlab.com/vojko.pribudic.foss/pre-commit-update'
    rev: v0.3.2
    hooks:
    -   id: pre-commit-update

stdout:

pre-commit-update........................................................Failed
- hook id: pre-commit-update
- files were modified by this hook

pre-commit-update - v0.3.1 -> v0.3.2 ✘
Changes detected and applied

Type (select one)

• Bug
• Feature request
• Suggestion

Pre-submit criteria

• No similar issue/feature request/suggestion exists I was asked to submit this anyways.
• Correct labels have been set for this issue/feature request/suggestion