Update instructions on doc testing

Author: ValerianRey

AGENTS.md

@@ -6,9 +6,6 @@
 - We use uv for everything (e.g. we do `uv run python ...` to run some python code, and
   `uv run pytest tests/unit` to run unit tests). Please prefer `uv run python -c ...` over
   `python3 -c ...`
-- When you create or modify a code example in a public docstring, always update the corresponding
-  doc test in the appropriate file of `tests/doc`. This also applies to any change in an example of
-  a `.rst` file, that must be updated in the corresponding test in `tests/doc/test_rst.py`.
 - After generating code, please run `uv run ty check`, `uv run ruff check` and `uv run ruff format`.
   Fix any error.
 - After changing anything in `src` or in `tests/unit` or `tests/doc`, please identify the affected

CONTRIBUTING.md

@@ -99,10 +99,9 @@ uv run pre-commit install
      CUBLAS_WORKSPACE_CONFIG=:4096:8 PYTEST_TORCH_DEVICE=cuda:0 uv run pytest tests/unit
      ```
 
-   - To check that the usage examples from docstrings and `.rst` files are correct, we test their
-   behavior in `tests/doc`. To run these tests, do:
+   - To check that the usage examples from docstrings and `.rst` files are correct, run:
      ```bash
-     uv run pytest tests/doc
+     uv run make doctest -C docs
      ```
 
   - To compute the code coverage locally, you should run the unit tests and the doc tests together,