Update dependency gulp-babel to v8

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
gulp-babel	^7.0.0 -> ^8.0.0

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Release Notes

babel/gulp-babel (gulp-babel)

### [`v8.0.0`](https://togithub.com/babel/gulp-babel/blob/HEAD/CHANGELOG.md#800-beta2-2018-03-14) [Compare Source](https://togithub.com/babel/gulp-babel/compare/v7.0.1...v8.0.0) - **\[Fix]** Fix for `sourceMapTarget` removal in Babel v7.0.0-beta.41 ([#​149](https://togithub.com/babel/gulp-babel/pull/149))

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Configuration

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[codecov[bot]]

Codecov Report

Merging #25 (b6b45d2) into main (8a7e61d) will not change coverage. Report is 4 commits behind head on main. The diff coverage is n/a.

:exclamation: Current head b6b45d2 differs from pull request most recent head 256f229. Consider uploading reports for the commit 256f229 to get more accurate results

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  Coverage   68.42%   68.42%           
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  Files           2        2           
  Lines          38       38           
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  Hits           26       26           
  Misses         12       12