Uniform `Header.vue` translations by using `$t` in `template` section

[MilosPaunovic]

As the createI18n function called inside kestra/ui/src/translations/i18n.ts automatically exposes global properties to templates - including the $t helper - we want to uniform the code and use $t exclusively in the <template> section of Vue files for translations.

This issue covers applying that cleanup only to the following file:
kestra/components/dashboard/components/Header.vue

Contribution instructions

• Replace all template usages of t('…') with $t('…') inside <template> section.
• Ensure that translation keys continue to work correctly in the UI.
• Do not modify script sections at all.
• Commit your changes following the repository's commit conventions.

Why this issue is great for new contributors?

• You'll get hands-on experience with the UI part of the Kestra codebase.
• The change is small, focused, and safe, making it a perfect entry point.

Only contributions from first-time contributors to this repository are accepted for this issue. 🚀

[MdTanwer]

Hey @MilosPaunovic I’d like to work on this issue. Could you please assign it to me?

[MilosPaunovic]

Hey @MdTanwer ,

Thank you so much for your interest in working on this issue! As stated in the description, we'd like to reserve this opportunity for contributors who haven't worked on this repository yet.

If you're willing to contribute and don't have anything currently assigned to you, you might want to check our curated list of good first issues to see if there's something that interests you and that you feel confident tackling independently.

[MdTanwer]

@MilosPaunovic Thank you for the clarification and for pointing me to the good first issues list. I really appreciate the support and will check it out.

[CodeByAfroj]

Hi! This is my second contribution to Kestra.
I’ve addressed issue #13896 by replacing t() with $t() in the template.
Looking forward to your review. Thanks!

[MilosPaunovic]

Hi there, @CodeByAfroj! 👋

Thanks for your interest in contributing and for opening this PR!

As a general open-source convention, it’s best to first comment on the issue to express your interest and wait until you're assigned before starting any work. This helps avoid overlapping efforts and keeps contributions coordinated.

We really appreciate your enthusiasm and look forward to future contributions! 🙌

[Rohith-patel-uppunuthula]

Hi! @MilosPaunovic I would love to work on this issue.
I’ve gone through the contributing guide and currently don’t have any issues assigned.
Please let me know if I can take this up. Thanks!