Update ExternalLinkFill.yml (#3673)

Bug: icon was marked as "new tab" but the icon for new tab is an box with the arrow stopping at the border. Having the new tab synonym here will cause missunderstandings.

Author: Camulos

@navikt/aksel-icons/icons/ExternalLinkFill.yml

@@ -5,7 +5,6 @@ keywords:
   - lenke
   - kobling
   - videresending
-  - new tab
   - ekstern side
   - eksternt
 variant: Fill