All users with Workspace Owner role can remove users from the workspace.
Here is the short guide for you.
Click on the workspace icon in the top left corner.
In the dropdown menu that appears click on “Settings”
Then click on “Members” tab in the left panel
This list will contain all members of your workspace (all who have joined your workspace and users you invited)
Click on the user you want to remove from your Workspace
The side drawer will open with the details of the user.
In the bottom right corner click on “Remove Member” button
A modal will appear asking you to confirm. Click on “Remove” button to confirm your choice and have that user removed.
Note. Same flow works to cancel invitation to your workspace for someone who hasn't joined your workspace yet.