fix: use outlined button as registering existing component is not a primary action

Signed-off-by: Carl-Erik Bergström <cbergstrom@spotify.com>

.changeset/hungry-buckets-repair.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder': patch
+---
+
+Change "Register Existing Component" CTA to outlined as it's not a primary action on the scaffolder pages

plugins/scaffolder/src/alpha/components/TemplateListPage/RegisterExistingButton.tsx

@@ -61,7 +61,7 @@ export const RegisterExistingButton = (props: RegisterExistingButtonProps) => {
       <AddCircleOutline />
     </IconButton>
   ) : (
-    <Button component={RouterLink} variant="contained" color="primary" to={to}>
+    <Button component={RouterLink} variant="outlined" color="primary" to={to}>
       {title}
     </Button>
   );