fix: do not use window.open for links in readonly mode (#4073)

* fix: do not use window.open for links in readonly mode

When `contenteditable` is `true`, the browser doesn't allow
direct link opens on clicking the `a` element. This is why we
need to call `window.open` to open our links.

However, when `contenteditable` is `false`, the default
browser mechanism for opening links works and there is no
need for using `window.open`.

* fix: linting errors

packages/extension-link/src/helpers/clickHandler.ts

@@ -22,7 +22,9 @@ export function clickHandler(options: ClickHandlerOptions): Plugin {
         const target = link?.target ?? attrs.target
 
         if (link && href) {
-          window.open(href, target)
+          if (view.editable) {
+            window.open(href, target)
+          }
 
           return true
         }