chore(deps): update dependency @portabletext/toolkit to ^2.0.12 (#6042)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

packages/@sanity/portable-text-editor/package.json

@@ -77,7 +77,7 @@
   "devDependencies": {
     "@jest/globals": "^29.7.0",
     "@playwright/test": "^1.41.2",
-    "@portabletext/toolkit": "^2.0.11",
+    "@portabletext/toolkit": "^2.0.12",
     "@sanity/diff-match-patch": "^3.1.1",
     "@sanity/ui": "^2.0.10",
     "@testing-library/react": "^13.4.0",