ci: allow image and release devbox bootstrap egress

[komer3]

Summary

• allow get.jetify.com:443 and get.jetpack.io:443 in the image and release workflows
• add workflow_dispatch to Image and Release so the workflow changes can be validated on-branch

Why

• recent harden-runner block-mode failures in the image/release devbox bootstrap path showed get.jetify.com was blocked
• ci-test debugging showed the installer path also resolves through get.jetpack.io, so both hosts are needed

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.42%. Comparing base (ce6ff7b) to head (bdb9303).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #129   +/-   ##
=======================================
  Coverage   75.42%   75.42%           
=======================================
  Files          38       38           
  Lines        2828     2828           
=======================================
  Hits         2133     2133           
  Misses        508      508           
  Partials      187      187           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.