Add checksums for darwin/arm64

[ashpect]

What this PR does / why we need it:

Add checksum for darwin/arm64 for dev-dependencies.

Which issue(s) this PR fixes:

Fixes #1288

Does this PR introduce a user-facing change?

NONE

Additional Notes for your reviewer:

Before the fix :

dependencies.go:83: downloading ytt: not supported on platform darwin/arm64
exit status 1

After the fix :

dependencies.go:175: ytt downloaded
dependencies.go:186: ytt validated
dependencies.go:175: kbld downloaded
dependencies.go:186: kbld validated
dependencies.go:175: vendir downloaded
dependencies.go:186: vendir validated
dependencies.go:175: kapp downloaded
dependencies.go:186: kapp validated

Review Checklist:

• [x ] Follows the developer guidelines
• Relevant tests are added or updated
• Relevant docs in this repo added or updated
• [] Relevant carvel.dev docs added or updated in a separate PR and there's
  a link to that PR
• Code is at least as readable and maintainable as it was before this
  change

[praveenrewar]

LGTM!