Upgrade transformers to fix CI (#17823)
Python package pipeline fails due to "tokenizers" compilation. Since
"tokenizers" is a dep of "transformers", we update its version and hope
a new solution had been there.
```
error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
--> tokenizers-lib/src/models/bpe/trainer.rs:517:47
```
