Bump gulp-pug from 3.3.0 to 4.0.1 (#272)

Bumps [gulp-pug](https://github.com/gulp-community/gulp-pug) from 3.3.0 to 4.0.1.
- [Release notes](https://github.com/gulp-community/gulp-pug/releases)
- [Changelog](https://github.com/gulp-community/gulp-pug/blob/master/CHANGELOG.md)
- [Commits](https://github.com/gulp-community/gulp-pug/compare/v3.3.0...v4.0.1)

---
updated-dependencies:
- dependency-name: gulp-pug
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -117,7 +117,7 @@
     "gulp-eslint": "^3.0.1",
     "gulp-jsonlint": "^1.0.2",
     "gulp-protractor": "^3.0.0",
-    "gulp-pug": "^3.0.4",
+    "gulp-pug": "^4.0.1",
     "gulp-run": "^1.6.12",
     "gulp-util": "^3.0.7",
     "html-loader": "^0.5.5",