fix: load multiple env files by convention

[sweatybridge]

What kind of change does this PR introduce?

Bug fix https://github.com/supabase/cli/issues/1518

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 8786730835

Details

• 17 of 22 (77.27%) changed or added relevant lines in 1 file are covered.
• 8 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.01%) to 58.235%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/utils/config.go	17	22	77.27%
<!--	Total:	17	22

Files with Coverage Reduction	New Missed Lines	%
internal/utils/config.go	1	54.84%
internal/storage/rm/rm.go	2	92.86%
internal/gen/keys/keys.go	5	11.76%
<!--	Total:	8

Totals
Change from base Build 8783012926:	0.01%
Covered Lines:	6527
Relevant Lines:	11208

---

💛 - Coveralls