chore(style): remove trailing_commas lint rule

[grdsdev]

What kind of change does this PR introduce?

I think latest flutter version removed the trailing_commas lint rule as CI started to fail: https://github.com/supabase/supabase-flutter/actions/runs/19325526766/job/55588812938

[coveralls]

Pull Request Test Coverage Report for Build 19431108203

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 79.847%

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Totals
Change from base Build 19325526769:	0.0%
Covered Lines:	3344
Relevant Lines:	4188

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💛 - Coveralls