Down arrow should not be rendered on SelectControl when multiple = false

[JohnRDOrazio]

Description

A down arrow / chevron is rendered on all SelectControl components, whether or not the multiple property / attribute is set to true. It should not be needed when multiple:true because there is no dropdown in this case.

Step-by-step reproduction instructions

Create a SelectControl component, and set the multiple property to true.

Expected behaviour

No down arrow should be rendered.

Actual behaviour

A down arrow is rendered.

Screenshots or screen recording (optional)

Code snippet (optional)

WordPress information

• WordPress version: 5.6.1
• Gutenberg version: 9.9.0
• Are all plugins except Gutenberg deactivated? No
• Are you using a default theme (e.g. Twenty Twenty-One)? No

Device information

• Device:
• Operating system:
• Browser:

I created PR #28817 to fix this. (not tested, needs review and testing)

[talldan]

This is easy to reproduce in the storybook - https://wordpress.github.io/gutenberg/?path=/story/components-selectcontrol--default.

[talldan]

I see this is already tracked in https://github.com/WordPress/gutenberg/issues/27166, so will consolidate the issues by closing this as a duplicate.