llama : add ability to cancel model loading (#4462)

llama : add ability to cancel model loading (#4462)

* llama : Add ability to cancel model load

Updated llama_progress_callback so that if it returns false, the model
loading is aborted.

* llama : Add test for model load cancellation

* Fix bool return in llama_model_load, remove std::ignore use

* Update llama.cpp

Co-authored-by: Jared Van Bortel <redacted>
* Fail test if model file is missing

* Revert "Fail test if model file is missing"

This reverts commit 32ebd525bf7e5a87ee8a3dbaab3d92ce79fbf23d.

* Add test-model-load-cancel to Makefile

* Revert "Revert "Fail test if model file is missing""

This reverts commit 2796953257ee5383fa7c8fe8fa8fc888c048fb0b.

* Simplify .gitignore for tests, clang-tidy fixes

* Label all ctest tests

* ci : ctest uses -L main

* Attempt at writing ctest_with_model

* ci : get ci/run.sh working with test-model-load-cancel

* ci : restrict .github/workflows/build.yml ctest to -L main

* update requirements.txt

* Disable test-model-load-cancel in make

* Remove venv before creation

* Restructure requirements.txt

Top-level now imports the specific additional requirements for each
python file. Using `pip install -r requirements.txt` will fail if
versions become mismatched in the per-file requirements.

* Make per-python-script requirements work alone

This doesn't break the main requirements.txt.

* Add comment

* Add convert-persimmon-to-gguf.py to new requirements.txt scheme

* Add check-requirements.sh script and GitHub workflow

* Remove shellcheck installation step from workflow

* Add nocleanup special arg

* Fix merge

see: https://github.com/ggerganov/llama.cpp/pull/4462#discussion_r1434593573

* reset to upstream/master

* Redo changes for cancelling model load

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Co-authored-by: Georgi Gerganov <redacted>
Co-authored-by: Jared Van Bortel <redacted>