Cleanup gulp scripts regarding bsCss

[david-poindexter]

Describe the enhancement

There are leftover gulp scripts still in gulpfile.js for the old method of handling Bootstrap CSS in the build. They need to be removed.

To Reproduce

View gulpfile.js and see bsCssInit() function.

Expected behavior

It behaves properly now - the old code just needs to be removed.

Screenshots

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Errors

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Additional context

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