chore: add CODEOWNERS file

[mruiz-ledger]

Description

Please provide a detailed description of what was done in this PR.
(And mention any links to an issue docs)

Changes include

• Bugfix (non-breaking change that solves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)
• Tests
• Documentation
• Other (for changes that might not fit in any category)

Breaking changes

Please complete this section if any breaking changes have been made, otherwise delete it.

Additional comments

Please post additional comments in this section if you have them, otherwise delete it.

Auto cherry-pick in API_LEVEL

If requested to port the commits from this PR on a dedicated API_LEVEL branch,
select the targeted one(s), or add new references if not listed:

[ ] TARGET_API_LEVEL: API_LEVEL_25
[ ] TARGET_API_LEVEL: API_LEVEL_26

This will only create the PR with cherry-picks, ready to be reviewed and merged.

Remember:

• The merge will ALWAYS be a manual operation.
• It is possible the cherry-picks don't apply correctly, mainly if previous commits have been forgotten.
• In case of failure, there is no other solution than redo the operation manually...

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.80%. Comparing base (c97a21e) to head (9346c71).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1495   +/-   ##
=======================================
  Coverage   91.80%   91.80%           
=======================================
  Files          37       37           
  Lines        4282     4282           
  Branches      524      524           
=======================================
  Hits         3931     3931           
  Misses        260      260           
  Partials       91       91           

Flag	Coverage Δ
unittests	91.80% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.