Add a yaml linter for our PRs.

Currently our yaml files seems to have some issues with the style and indentation. We should add a way to make them standardized and running a check on these files to avoid inconsistencies.

These do not break our tests nor workflows but I believe that this should be handled properly.

Review the repository's YAML files and existing pull-request checks first, then inspect how current tests and workflows are configured. Choose a YAML linting approach that matches the project and define the style rules to enforce. Done means the PR check consistently flags YAML style and indentation issues without disrupting existing tests or workflows.

Written by the indexing model from the issue text.