Formatting breaks with default settings when yaml.format.printWidth is 80 but key is longer

Describe the bug

Certain YAML contents are erroneously converted into a weird non-yaml ternary-expression-like string.

Expected Behavior

Formatting should generate valid YAML even for long keys.

Current Behavior

The default yaml.format.printWidth is 80 characters. If the key is longer, questionmarks are added before keys when formatting.

For example, this:

resource.customizations.ignoreDifferences.admissionregistration.k8s.io_MutatingWebhookConfiguration: |
      jqPathExpressions:
        - '.webhooks[]?.clientConfig.caBundle'

Gets formatted into this:

? resource.customizations.ignoreDifferences.admissionregistration.k8s.io_MutatingWebhookConfiguration
    : |
      jqPathExpressions:
        - '.webhooks[]?.clientConfig.caBundle'

But this:

resource.customizations.ignoreDifferences.admissionregistration.k8s.io_Mutating: |
      jqPathExpressions:
        - '.webhooks[]?.clientConfig.caBundle'

Turns into:

resource.customizations.ignoreDifferences.admissionregistration.k8s.io_Mutating:
  |
  jqPathExpressions:
    - '.webhooks[]?.clientConfig.caBundle'

Steps to Reproduce

1. Create YAML with contents:

   resource.customizations.ignoreDifferences.admissionregistration.k8s.io_MutatingWebhookConfiguration: |
     jqPathExpressions:
       - '.webhooks[]?.clientConfig.caBundle'
   

2. Try formatting and see results:

   ? resource.customizations.ignoreDifferences.admissionregistration.k8s.io_MutatingWebhookConfiguration
   : |
     jqPathExpressions:
       - '.webhooks[]?.clientConfig.caBundle'
   

Environment

• Windows
• Mac
• Linux
• other (please specify)

Reproduce the formatting behavior using the YAML examples and the default yaml.format.printWidth setting. Trace the formatter entry point responsible for wrapping long keys, then verify that formatting preserves valid YAML for both long and shorter keys.