!reference[key, subkey] is marked as an error: YAML unresolved flag

Checklist

• I'm using the latest version of the extension (see the latest version in the right column of this page)
  • Extension version: Put your extension version here
• I'm using the latest VS Code version (find the latest version here)
  • VS Code version: Put your VS Code version here
• I'm using a supported version of GitLab (see README for the supported version)
  • GitLab version: Put your GitLab version here, or say "happens on gitlab.com"

Summary

Steps to reproduce

test.yml:

.common:
  script:
    - echo TEST

test:
  stage: test
  script:
    - !reference[.common, script]

What is the current bug behavior?

!reference[.common, script] is underlined red as an error:

Unresolved tag: !reference YAML
gitlab-ci
source: ci.json

What is the expected correct behavior?

!reference gitlab specific YAML tag should not be reported as an error.

Relevant logs and/or screenshots

Possible fixes