CTranslate2 3.4.0

Fixes and improvements

• Fix incorrect vocabulary in M2M100 models after conversion with transformers>=4.24
• Fix incorrect model outputs when executing with very large batch sizes on GPU
• Fix memory error in biased decoding: the vector of divergence was read and updated past its length
• Allow setting prefix_bias_beta > 0 with beam_size == 1
• Prevent timestamps from decreasing during Whisper generation
• Make some error messages more helpful when implementing a custom converter