Feat: add test encryption public key

What does this MR do and why?

Related upstream MR https://gitlab.com/gitlab-org/gitlab/-/merge_requests/122951/diffs

Fix pipeline https://jihulab.com/gitlab-cn/gitlab/-/jobs/8024445

To fix the pipeline, we should add a test encryption public key to the jh folder.

This key is from our license staging environment.

➜  jh git:(add-test-decryption-key) ✗ md5 .license_encryption_key.pub
MD5 (.license_encryption_key.pub) = 889e2575e9c1b0e81483b6963e6736b3
➜  jh git:(add-test-decryption-key) ✗ md5 .test_license_encryption_key.pub
MD5 (.test_license_encryption_key.pub) = b0779672d0f444e08472bfda6b2fa708

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Before	After

How to set up and validate locally

running rails gettext:lint without seeing that warning

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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