Fetch stack templates without GitHub API in `stack new`

[matsubara0507]

stack new use GitHub API to fetch template from GitHub (for main default branch) #5447

But, unauthenticated GitHub API has rate limit allows for up to 60 requests per hour.
ref: https://docs.github.com/en/rest/overview/resources-in-the-rest-api#rate-limiting

If possible, I want to stack new is not depend to GitHub API.
GitHub RAW URL can fetch default branch resource using HEAD branch:
https://raw.githubusercontent.com/commercialhaskell/stack/HEAD/README.md
https://raw.githubusercontent.com/matsubara0507/github-graphql-example.hs/HEAD/README.md <- default is main

FYI: GitLab and Bitbucket too
https://gitlab.haskell.org/ghc/ghc/raw/HEAD/README.md
https://bitbucket.org/khibino/haskell-relational-record/raw/HEAD/README.md

So, How about stack new use HEAD branch instead of GitHub API ?

However, I’m concerned document is not exist about HEAD branch.

[mpilgrem]

Closing, as related to #6034 and that has been resolved by:

• Stack will use the value of the GH_TOKEN, or GITHUB_TOKEN, environment
  variable as credentials to authenticate its GitHub REST API requests.