fix(fastboot): fix start:fastboot script

[VasylMarchuk]

Closes #3612

Brief

This is an attempt to fix a dreaded import error that's been happening for 2+ years when running bun run start:fastboot task and visiting the app locally.

Details

TBD: Currently in this PR, bun run start:fastboot is fixed, but ember build is broken

Checklist

• I've thoroughly self-reviewed my changes
• I've added tests for my changes, unless they affect admin-only areas (or are otherwise not worth testing)
• I've verified any visual changes using Percy (add a commit with [percy] in the message to trigger)

[github-actions]

Test Results

  1 files  ±0    1 suites  ±0   7m 12s ⏱️ - 3m 54s
699 tests ±0  644 ✅ +2  55 💤 ±0  0 ❌ ±0 
714 runs  ±0  659 ✅ +4  55 💤 ±0  0 ❌  - 2 

Results for commit 4188ebe. ± Comparison against base commit f515dcc.

♻️ This comment has been updated with latest results.

[codecov]

Codecov Report

❌ Patch coverage is 47.05882% with 9 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
app/initializers/ember-cli-mirage.js	47.05%	9 Missing ⚠️

❌ Your patch status has failed because the patch coverage (47.05%) is below the target coverage (100.00%). You can increase the patch coverage or adjust the target coverage.

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