feat(cli): parallelize container image pulls in supabase cli start

[avallete]

What kind of change does this PR introduce?

Bug fix, feature, docs update, ...

What is the current behavior?

Please link any relevant issues here.

What is the new behavior?

Feel free to include screenshots if it includes visual changes.

Additional context

Add any other context or screenshots.

[coveralls]

Pull Request Test Coverage Report for Build 19361061656

Details

• 213 of 384 (55.47%) changed or added relevant lines in 3 files are covered.
• 18 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.1%) to 54.952%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/utils/retry.go	20	24	83.33%
internal/utils/docker.go	34	116	29.31%
internal/start/start.go	159	244	65.16%

Files with Coverage Reduction	New Missed Lines	%
internal/storage/rm/rm.go	2	80.61%
internal/gen/keys/keys.go	5	12.9%
internal/utils/docker.go	11	62.55%

Totals
Change from base Build 19354265713:	-0.1%
Covered Lines:	6703
Relevant Lines:	12198

---

💛 - Coveralls