fix: swap yamljs with yaml

[mamerruddin]

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Closing issues

closes #1572

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Potential Problems With The Approach

Test plan

Change config file in tests/esm to yaml format just to show it loads config correctly.

[mamerruddin]

Closes #1572 . Swapped yamljs with yaml as it is actively maintained, and has zero dependency.

[mamerruddin]

I have modify test to see it ables to load config correctly from a yaml config file.