Disables validation for inactive Jira integration

What does this MR do and why?

By default, we don't validate integrations when they are not set to active.

We want to be able to save inactive integrations without providing project_key.

Currently we are receiving following error:

The form contains the following error:

Project key can't be blank

Expected behaviour:

 Jira settings saved, but not active.

Screenshots or screen recordings

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How to set up and validate locally

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

1. Visit any project's integration page such as http://localhost:3000/flightjs/Flight/-/settings/integrations
2. Scroll down to Jira inside the Add an integration section
3. Click on the Jira link
4. Uncheck the Active checkbox and check the Enable Jira issues checkbox
5. Click on the Save changes button

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #357810 (closed)