FIX Type annoations in vera/bnb.py (#2139)

The file was missing the from __future__ import annotations part. As
this code is only running nightly with GPU, the normal CI missed this
omission.

src/peft/tuners/vera/bnb.py

@@ -11,6 +11,7 @@
 # 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.
+from __future__ import annotations
 
 import warnings
 from typing import Optional