support: the default cachedir seems incorrect without actions/setup-go step

[razonyang]

Checklist

• I am using the latest version of this action.
• I have read the latest README and followed the instructions.
• I have read the latest GitHub Actions official documentation and learned the basic spec and concepts.

Describe your question

I noticed that my workflow always say there is no Hugo modules cached found. And I create a testing repo for checking the path of cachedir, it's different (/tmp/hugo_cache_runner/) with the one (/home/runner/.cache/hugo_cache) on README.

Relevant links

Public repository: https://github.com/razonyang/github-workflows-testing
YAML config: 
YAML workflow: https://github.com/razonyang/github-workflows-testing/blob/main/.github/workflows/hugo-modules-caching.yml

Relevant log output

Additional context.

Full logs are available on https://github.com/razonyang/github-workflows-testing/actions/runs/8252748983/job/22573007579.