build(deps-dev): bump ejs from 2.7.4 to 3.1.7

Bumps [ejs](https://github.com/mde/ejs) from 2.7.4 to 3.1.7.
- [Release notes](https://github.com/mde/ejs/releases)
- [Changelog](https://github.com/mde/ejs/blob/main/CHANGELOG.md)
- [Commits](mde/ejs@v2.7.4...v3.1.7)

---
updated-dependencies:
- dependency-name: ejs
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -88,7 +88,7 @@
     "core-js": "^2.6.5",
     "cross-env": "^5.2.0",
     "css-loader": "^2.1.0",
-    "ejs": "^2.6.1",
+    "ejs": "^3.1.7",
     "gulp": "^4.0.0",
     "gulp-htmllint": "^0.0.16",
     "gulp-stylelint": "^8.0.0",