git sha256 support

[wraithgar]

Epic

With the release of git 2.51 support for sha-256 hashes in git references has become something to plan for. Currently npm assumes a 40 sha-1 hash length for git, and that will need to update if we want to support sha-256.

A (growing) list of places that likely need change (or at least tests)

• https://github.com/npm/hosted-git-info
  • chore: explicit sha-1 and sha-256 git committish tests hosted-git-info#324
• https://github.com/npm/npm-package-arg
  • chore: explicit sha1 / sha256 git committish tests npm-package-arg#220
• https://github.com/npm/git
  • chore: explicit sha-1 and sha-256 git committish tests git#233
• https://github.com/npm/pacote
  • feat: add support for git-256 sha lengths pacote#445
• https://github.com/npm/cli
  • feat: add support for git-256 sha lengths cli#8968

[wraithgar]

I think we're covered. If we missed something we'll bugfix.