feat: license headers ignore prettier-ignored files

[kevgo]

Don't add license header to prettier-ignored files.

Related Issue or Design Document

https://github.com/ory-corp/general/issues/602

Checklist

• I have read the contributing guidelines
  and signed the CLA.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got approval (please contact
  security@ory.sh) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added the necessary documentation within the code base (if
  appropriate).