chore: sync text-generation version from 0.3.0 to 0.6.0 with pyproject.toml (#950)

# What does this PR do?

sync the version for text-generation.

clients/python/text_generation/__init__.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "0.3.0"
+__version__ = "0.6.0"
 
 from text_generation.client import Client, AsyncClient
 from text_generation.inference_api import InferenceAPIClient, InferenceAPIAsyncClient