ci: abort if build requirements are missing

[nikwen]

Overview

Running CI locally was failing for me and it wasn't obvious from the error message why.

This PR makes it easier for contributors to figure out what's going on:

1. Abort CI if build requirements are missing.
2. Check that Git LFS has been configured.
3. Fix formatting by adding trailing newlines to log messages. (Otherwise, the output is harder to read.)

Additional information

Error message that I got

16/44 Test #16: test-tokenizers-ggml-vocabs .......***Failed    0.66 sec
Already up to date.
/Users/nikwen/Projects/ML/llama.cpp/tests/test-tokenizers-repo.sh: line 35: shopt: globstar: invalid shell option name
main : reading vocab from: '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/HybridDNA/ggml-vocab-carbon.gguf'
register_backend: registered backend CPU (1 devices)
register_device: registered device CPU (Apple M4 Pro)
gguf_init_from_reader: invalid magic characters: 'vers', expected 'GGUF'
llama_model_load: error loading model: llama_model_loader: failed to load model from /Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/HybridDNA/ggml-vocab-carbon.gguf
llama_model_load_from_file_impl: failed to load model
main: error: failed to load vocab '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/HybridDNA/ggml-vocab-carbon.gguf'
main : reading vocab from: '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/PLaMo2/ggml-vocab-plamo2.gguf'
register_backend: registered backend CPU (1 devices)
register_device: registered device CPU (Apple M4 Pro)
gguf_init_from_reader: invalid magic characters: 'vers', expected 'GGUF'
llama_model_load: error loading model: llama_model_loader: failed to load model from /Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/PLaMo2/ggml-vocab-plamo2.gguf
llama_model_load_from_file_impl: failed to load model
main: error: failed to load vocab '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/PLaMo2/ggml-vocab-plamo2.gguf'
main : reading vocab from: '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/RWKV/ggml-vocab-rwkv-7-world.gguf'
register_backend: registered backend CPU (1 devices)
register_device: registered device CPU (Apple M4 Pro)
gguf_init_from_reader: invalid magic characters: 'vers', expected 'GGUF'
llama_model_load: error loading model: llama_model_loader: failed to load model from /Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/RWKV/ggml-vocab-rwkv-7-world.gguf
llama_model_load_from_file_impl: failed to load model
main: error: failed to load vocab '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/RWKV/ggml-vocab-rwkv-7-world.gguf'
main : reading vocab from: '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/SPM/ggml-vocab-gemma-3.gguf'
register_backend: registered backend CPU (1 devices)
register_device: registered device CPU (Apple M4 Pro)
gguf_init_from_reader: invalid magic characters: 'vers', expected 'GGUF'
llama_model_load: error loading model: llama_model_loader: failed to load model from /Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/SPM/ggml-vocab-gemma-3.gguf
llama_model_load_from_file_impl: failed to load model
main: error: failed to load vocab '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/SPM/ggml-vocab-gemma-3.gguf'
main : reading vocab from: '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/UGM/ggml-vocab-nomic-bert-moe.gguf'
register_backend: registered backend CPU (1 devices)
register_device: registered device CPU (Apple M4 Pro)
gguf_init_from_reader: invalid magic characters: 'vers', expected 'GGUF'
llama_model_load: error loading model: llama_model_loader: failed to load model from /Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/UGM/ggml-vocab-nomic-bert-moe.gguf
llama_model_load_from_file_impl: failed to load model
main: error: failed to load vocab '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/UGM/ggml-vocab-nomic-bert-moe.gguf'
main : reading vocab from: '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/WPM/ggml-vocab-jina-v2-en.gguf'
register_backend: registered backend CPU (1 devices)
register_device: registered device CPU (Apple M4 Pro)
gguf_init_from_reader: invalid magic characters: 'vers', expected 'GGUF'
llama_model_load: error loading model: llama_model_loader: failed to load model from /Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/WPM/ggml-vocab-jina-v2-en.gguf
llama_model_load_from_file_impl: failed to load model
main: error: failed to load vocab '/Users/nikwen/Projects/ML/llama.cpp/models/ggml-vocabs/WPM/ggml-vocab-jina-v2-en.gguf'

Turns out you need to have Git LFS installed and configured, which I didn't have.

The existing check for this didn't abort the run. Thus, I missed its short message in a huge wall of text.

Requirements

• I have read and agree with the contributing guidelines
• AI usage disclosure: YES. Changes made manually. Opus 5 did a review pass.

[nikwen]

@taronaeo Would you have time to take a look at another CI PR? Thank you so much in advance! :)

[taronaeo]

Thanks! This is easily missed when setting up CI :)

[nikwen]

I missed it locally. Thanks for your review! :)