Fix crash when using grammar

[tc-wolf]

Upstream changed some things w/ how grammar works in ggerganov/llama.cpp#8508 and ggerganov/llama.cpp#8093 - may also want to check if llama_grammar_init return value is null, since this is what's done now rather than throwing an error.

Old argument order for llama_grammar_accept_token was:
llama_grammar_accept_token(ctx, grammar, token)

Now this is:
llama_grammar_accept_token(grammar, ctx, token)

Can test with

model = llama_cpp.Llama("bartowski/Meta-Llama-3.1-8B-Instruct-GGUF/Meta-Llama-3.1-8B-Instruct-Q8_0.gguf", n_ctx=4096, n_gpu_layers=-1, offload_kqv=True, n_batch=1024, n_threads=12, n_threads_batch=12, verbose=True)
model.create_chat_completion(
    messages=[
        {
            "role": "system",
            "content": "You are a helpful assistant that outputs in JSON.",
        },
        {"role": "user", "content": "Who won the world series in 2020"},
    ],
    response_format={
        "type": "json_object",
        "schema": {
            "type": "object",
            "properties": {"team_name": {"type": "string"}},
            "required": ["team_name"],
        },
    },
    temperature=0.7,
)

Should fix #1623

[abetlen]

@tc-wolf thank you so much!