docs: add warning note on self-hosted github runners

CONTRIBUTING.md

@@ -137,9 +137,9 @@ To preview any changes to the documentation locally:
 
 1. Install the [Rust toolchain](https://www.rust-lang.org/tools/install).
 
-1. Run `cargo dev generate-all`, to update any auto-generated documentation.
+2. Run `cargo dev generate-all`, to update any auto-generated documentation.
 
-1. Run the development server with:
+3. Run the development server with:
 
  ```shell
  # For contributors.

docs/guides/integration/github.md

@@ -175,6 +175,30 @@ Its effect on performance is dependent on the packages being installed.
 
  If using `uv pip`, use `requirements.txt` instead of `uv.lock` in the cache key.
 
+!!! warning
+
+ [post-job-hook]: https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners/running-scripts-before-or-after-a-job
+
+ When using non-ephemeral self-hosted runners the default cache location can grow over time,
+ becoming problematic. In such cases its possible to set the caching location relative to the
+ GitHub Workspace and clean it once the job finishes using a [Post Job Hook][post-job-hook].
+
+ ```yaml
+ install_job:
+ env:
+ # Configure a relative location for the uv cache
+ UV_CACHE_DIR: ${{ github.workspace }}/.cache/uv
+ # ... restore uv cache ...
+ ```
+
+ Using a post job hook requires setting the `ACTIONS_RUNNER_HOOK_JOB_STARTED` environment
+ variable on the self-hosted runner to the path of a cleanup script such as the one shown below.
+
+ ```sh
+ #!/usr/bin/env sh
+ rm -rf $GITHUB_WORKSPACE/*
+ ```
+
 ## Using `uv pip`
 
 If using the `uv pip` interface instead of the uv project interface, uv requires a virtual