Remove outdated commands from the code style doc & point to the contributing guide. (#14773)

changelog.d/14773.doc

@@ -0,0 +1 @@
+Remove duplicate commands from the Code Style documentation page; point to the Contributing Guide instead.

docs/code_style.md

@@ -13,23 +13,14 @@ The necessary tools are:
 - [ruff](https://github.com/charliermarsh/ruff), which can spot common errors; and
 - [mypy](https://mypy.readthedocs.io/en/stable/), a type checker.
 
-Install them with:
-
-```sh
-pip install -e ".[lint,mypy]"
-```
-
-The easiest way to run the lints is to invoke the linter script as follows.
-
-```sh
-scripts-dev/lint.sh
-```
+See [the contributing guide](development/contributing_guide.md#run-the-linters) for instructions
+on how to install the above tools and run the linters.
 
 It's worth noting that modern IDEs and text editors can run these tools
 automatically on save. It may be worth looking into whether this
 functionality is supported in your editor for a more convenient
 development workflow. It is not, however, recommended to run `mypy`
-on save as they take a while and can be very resource intensive.
+on save as it takes a while and can be very resource intensive.
 
 ## General rules