fix: vertical alignment in token selector

What does this MR do?

Remove item alignment from token selector introduced in !2872 (merged).

NB: gl-align-items-center within token-container seems to only be activated when gl-display-flex was added to the parent, it is also removed as it is not active currently anyway.

	before	after
default height
with height gl-h-13!

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines.
• GitLab UI's contributing guidlines.
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• Added the ~"component:*" label(s) if applicable.

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

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Accessibility

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