fix(glm4v): version-aware hidden_size/vocab_size for Glm4vConfig

[1fanwang]

Reading config.hidden_size and config.vocab_size directly in glm4v.py and glm4v_moe.py fails on transformers v5+, where Glm4vConfig and Glm4vMoeConfig are composite (text_config + vision_config) and the top-level fields are no longer present. Reported in #1152:

File ".../liger_kernel/transformers/model/glm4v.py", line 130, in lce_forward
    hidden_size=self.config.hidden_size,
AttributeError: 'Glm4vConfig' object has no attribute 'hidden_size'

Same shape PR #1062 already fixed for Qwen2-VL / Qwen2.5-VL — mirror that helper (_get_hidden_size, _get_vocab_size) gated on transformers >= 5.0.0, applied to both glm4v.py and glm4v_moe.py. Pre-v5 still works because the helpers fall back to the top-level attribute. Helper signatures are typed (config: PretrainedConfig -> int) and the version flag is annotated bool.

Reproducer (transformers 5.7.0)

from transformers import Glm4vConfig
cfg = Glm4vConfig(text_config={"hidden_size": 1024, "vocab_size": 32000})
cfg.text_config.hidden_size   # 1024
cfg.hidden_size               # AttributeError: 'Glm4vConfig' object has no attribute 'hidden_size'

Same shape reproduces for Glm4vMoeConfig. Identical to the trace in #1152.

After the helper change, both _get_hidden_size(cfg) and _get_vocab_size(cfg) route through text_config on v5+ and fall back to the top-level attribute pre-v5:

transformers=5.7.0  v5_or_later=True
_get_hidden_size(Glm4vConfig)    = 1024
_get_vocab_size(Glm4vConfig)     = 32000
_get_hidden_size(Glm4vMoeConfig) = 1024
_get_vocab_size(Glm4vMoeConfig)  = 32000

Tests

End-to-end coverage already in place in test/convergence/bf16/test_mini_models.py and test/convergence/fp32/test_mini_models.py — both mini_glm4v and mini_glm4v_moe configs construct via the text_config sub-dict (lines 1245–1308 / 1311–1368), so CI exercises the fixed path on v5+ runners. No new test file added — matches the precedent set by PR #1062 (qwen2_vl fix), which also relied on the existing convergence tests rather than introducing a helper-level test layer.

Closes #1152.