Use relative path for the path linked to the cookie (backport #13664) (backport #13666)

[mergify]

Proposed Changes

This PR fixes a regression added to the management ui's oauth authentication. This regression occurs only when the ui is mounted on a custom path.

Use relative path for the path linked to the cookie used by manegement ui's oauth logic to store the token until it is moved onto the local storage.

Types of Changes

What types of changes does your code introduce to this project?
Put an x in the boxes that apply

• Bug fix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• Documentation improvements (corrections, new content, etc)
• Cosmetic change (whitespace, formatting, etc)
• Build system and/or CI

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This is an automatic backport of pull request #13664 done by [Mergify](https://mergify.com).

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This is an automatic backport of pull request #13666 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 63d95f8 has failed:

On branch mergify/bp/v4.0.x/pr-13666
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You are currently cherry-picking commit 63d95f89f.
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	both modified:   selenium/short-suite-management-ui

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