build(deps): bump prosemirror-transform from 1.3.4 to 1.4.0

Bumps [prosemirror-transform](https://github.com/prosemirror/prosemirror-transform) from 1.3.4 to 1.4.0.
- [Release notes](https://github.com/prosemirror/prosemirror-transform/releases)
- [Changelog](https://github.com/ProseMirror/prosemirror-transform/blob/master/CHANGELOG.md)
- [Commits](ProseMirror/prosemirror-transform@1.3.4...1.4.0)

---
updated-dependencies:
- dependency-name: prosemirror-transform
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -74,7 +74,7 @@
 		"prosemirror-model": "^1.16.1",
 		"prosemirror-schema-list": "^1.1.6",
 		"prosemirror-state": "^1.3.4",
-		"prosemirror-transform": "^1.3.4",
+		"prosemirror-transform": "^1.4.0",
 		"prosemirror-utils": "^1.0.0-0",
 		"prosemirror-view": "^1.23.9",
 		"proxy-polyfill": "^0.3.2",