build(deps): bump terser and gulp-uglify-es

Bumps [terser](https://github.com/terser/terser) to 5.15.1 and updates ancestor dependency [gulp-uglify-es](https://gitlab.com/itayronen/gulp-uglify-es). These dependencies need to be updated together.


Updates `terser` from 3.17.0 to 5.15.1
- [Release notes](https://github.com/terser/terser/releases)
- [Changelog](https://github.com/terser/terser/blob/master/CHANGELOG.md)
- [Commits](terser/terser@v3.17.0...v5.15.1)

Updates `gulp-uglify-es` from 1.0.4 to 3.0.0
- [Release notes](https://gitlab.com/itayronen/gulp-uglify-es/tags)
- [Changelog](https://gitlab.com/itayronen/gulp-uglify-es/blob/master/CHANGELOG.md)
- [Commits](https://gitlab.com/itayronen/gulp-uglify-es/commits/master)

---
updated-dependencies:
- dependency-name: terser
  dependency-type: indirect
- dependency-name: gulp-uglify-es
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -36,7 +36,7 @@
     "gulp-rename": "^1.2.2",
     "gulp-replace": "^1.0.0",
     "gulp-strip-comments": "^2.4.5",
-    "gulp-uglify-es": "^1.0.4",
+    "gulp-uglify-es": "^3.0.0",
     "merge-stream": "^1.0.1",
     "qunit": "^2.9.1",
     "read-dir-deep": "^7.0.1",