Caps max allowed version of transformers for vila.

v4.34.0 release did a complete refactor of the tokenizer
module, see:

huggingface/transformers#23909

Something about the difference is causing vila to
produce literally billions of lines of log warning messages
to Datadog in prod. I don't know if these warnings are
meaningful, but they are expensive.

pyproject.toml

@@ -88,7 +88,7 @@ hf_predictors = [
 ]
 vila_predictors = [
     'vila>=0.5,<0.6',
-    'transformers',
+    'transformers<4.34.0',
 ]
 mention_predictor = [
     'transformers[torch]',