fix: exclude directories for local migrations

[ahtcx]

What kind of change does this PR introduce?

I use an ORM that generates a meta directory in the migrations directory. This change should ignore any directories when listing local migrations.

What is the current behavior?

Currently the CLI outputs the following when a meta directory exists in the migrations directory:

Skipping migration meta... (file name must match pattern "<timestamp>_name.sql")

What is the new behavior?

Directories in the migrations directory will be skipped silently.

Additional context

I want to use the Supabase migrations instead of the built-in ORM migration tool as it integrates more smoothly into my workflow.

I'm not a Go dev and I don't have a dev environment set up but I figured this is a tiny change so it hopefully isn't an issue. I was initially going to create an issue but decided I might as well make it a PR, apologies if I missed anything! I can create an issue if this needs more work.

Thanks!

[coveralls]

Pull Request Test Coverage Report for Build 18392443203

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.03%) to 54.67%

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Files with Coverage Reduction	New Missed Lines	%
internal/gen/keys/keys.go	5	12.9%

Totals
Change from base Build 18366617803:	-0.03%
Covered Lines:	6409
Relevant Lines:	11723

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💛 - Coveralls

[sweatybridge]

Thanks for contributing. Looks like a good QoL fix.