fix a11y and remove outline on dialog

Signed-off-by: Sofia Sjöblad <ssjoblad@spotify.com>

packages/ui/src/components/Dialog/Dialog.styles.css

@@ -34,6 +34,7 @@
   max-width: calc(100vw - 3rem);
   display: flex;
   flex-direction: column;
+  outline: none;
 }
 
 /* Dialog entering animation */

packages/ui/src/components/Dialog/Dialog.tsx

@@ -53,7 +53,7 @@ export const DialogHeader = forwardRef<
       <Heading slot="title" className={classNames.headerTitle}>
         {children}
       </Heading>
-      <Button variant="tertiary" slot="close">
+      <Button name="close" aria-label="Close" variant="tertiary" slot="close">
         <RiCloseLine />
       </Button>
     </Flex>