[ci] fix: fix ci by downgrade transformers to <5 (verl-project#5143)

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Author: vermouth1992

.github/workflows/cpu_unit_tests.yml

@@ -95,7 +95,7 @@ jobs:
         run: |
           pip3 install -r requirements-test.txt
           pip3 install --no-deps -e .
-          pip3 install --upgrade transformers
+          pip3 install --upgrade "transformers<5.0.0"
       - name: Download datasets
         run: |
           python3 examples/data_preprocess/gsm8k.py --local_dataset_path ${HOME}/models/hf_data/gsm8k

.github/workflows/model.yml

@@ -99,7 +99,7 @@ jobs:
         run: |
           pip3 install -r requirements-test.txt
           pip3 install --no-deps -e .
-          pip3 install --upgrade transformers
+          pip3 install --upgrade "transformers<5.0.0"
       - name: Running rmpad model tests on 8 L20 GPUs + flash_attn 2.5.8
         run: |
           pytest -s tests/models/test_transformer.py

tests/trainer/config/legacy_ppo_megatron_trainer.yaml

@@ -175,7 +175,7 @@ actor_rollout_ref:
     tensor_model_parallel_size: 2
     max_num_batched_tokens: 8192
     max_model_len: null
-    max_num_seqs: 256
+    max_num_seqs: 1024
     log_prob_micro_batch_size: null # will be deprecated, use log_prob_micro_batch_size_per_gpu
     log_prob_micro_batch_size_per_gpu: null
     log_prob_use_dynamic_bsz: ${actor_rollout_ref.actor.use_dynamic_bsz}

tests/trainer/config/legacy_ppo_trainer.yaml

@@ -466,7 +466,7 @@ actor_rollout_ref:
     max_model_len: null
 
     # max length of sequences
-    max_num_seqs: 256
+    max_num_seqs: 1024
 
     # [Will be deprecated, use log_prob_micro_batch_size_per_gpu] The batch size for one forward pass in the computation of log_prob. Global batch size.
     log_prob_micro_batch_size: null