fix typo in license docstring (#14094)

last line: "# limitations under the License." is missing

examples/pytorch/audio-classification/run_audio_classification.py

@@ -12,6 +12,7 @@
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
+# limitations under the License.
 
 import logging
 import os