
This is not possible using SharePoint out of the box capabilities. But you can inject custom CSS using SPFx application customizer to hide this. Please refer to the following document and code
Build your first SharePoint Framework Extension.
SPFx Applications Customiser CSS Injection
After deploy the spfx extension you can insert css code like following
Then you can refer to following css to hide the button
button[title='Switch to other libraries on this site'] {
display: none !important;
}
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