Refactor version retrieval to use importlib.metadata for improved reliability

Author: qgallouedec

trl/__init__.py

@@ -12,18 +12,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from importlib.metadata import PackageNotFoundError, version
 from pathlib import Path
 from typing import TYPE_CHECKING
 
 from .import_utils import OptionalDependencyNotAvailable, _LazyModule, is_diffusers_available
 
 
-# Read version from VERSION file
-_version_file = Path(__file__).parent.parent / "VERSION"
 try:
-    with open(_version_file, encoding="utf-8") as f:
-        __version__ = f.read().strip()
-except FileNotFoundError:
+    __version__ = version("trl")
+except PackageNotFoundError:
     __version__ = "unknown"
 
 _import_structure = {