Add required PyPI classifiers for JupyterLab extension identification

Co-authored-by: ktaletsk <8834829+ktaletsk@users.noreply.github.com>

Author: Copilot

pyproject.toml

@@ -23,6 +23,9 @@ classifiers = [
     "Development Status :: 4 - Beta",
     "Framework :: Jupyter",
     "Framework :: Jupyter :: JupyterLab",
+    "Framework :: Jupyter :: JupyterLab :: 4",
+    "Framework :: Jupyter :: JupyterLab :: Extensions",
+    "Framework :: Jupyter :: JupyterLab :: Extensions :: Prebuilt",
     "Programming Language :: Python",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",