Bump the version to 3.4.0 ahead of the next release.

PiperOrigin-RevId: 818694877
Change-Id: I42e261956a0219e549bec6a54cbf330a74f02f9f

mjx/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name="mujoco-mjx"
-version = "3.3.7"
+version = "3.4.0"
 authors = [
     {name = "Google DeepMind", email = "mujoco@deepmind.com"},
 ]
@@ -29,7 +29,7 @@ dependencies = [
     "etils[epath]",
     "jax",
     "jaxlib",
-    "mujoco>=3.3.7.dev0",
+    "mujoco>=3.4.0.dev0",
     "scipy",
     "trimesh",
 ]
@@ -45,9 +45,9 @@ mjx-viewer = "mujoco.mjx.viewer:main"
 
 [project.urls]
 Homepage = "https://github.com/google-deepmind/mujoco/tree/main/mjx"
-Documentation = "https://mujoco.readthedocs.io/en/3.3.7"
+Documentation = "https://mujoco.readthedocs.io/en/3.4.0"
 Repository = "https://github.com/google-deepmind/mujoco/tree/main/mjx"
-Changelog = "https://mujoco.readthedocs.io/en/3.3.7/changelog.html"
+Changelog = "https://mujoco.readthedocs.io/en/3.4.0/changelog.html"
 
 [tool.isort]
 force_single_line = true