Bump grunt-contrib-uglify in /searx/static/themes/oscar

Bumps [grunt-contrib-uglify](https://github.com/gruntjs/grunt-contrib-uglify) from 5.0.1 to 5.1.0.
- [Release notes](https://github.com/gruntjs/grunt-contrib-uglify/releases)
- [Changelog](https://github.com/gruntjs/grunt-contrib-uglify/blob/main/CHANGELOG)
- [Commits](https://github.com/gruntjs/grunt-contrib-uglify/compare/v5.0.1...v5.1.0)

---
updated-dependencies:
- dependency-name: grunt-contrib-uglify
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

searx/static/themes/oscar/package.json

@@ -6,7 +6,7 @@
         "grunt-contrib-copy": "^1.0.0",
         "grunt-contrib-jshint": "~3.1.1",
         "grunt-contrib-less": "~3.0.0",
-        "grunt-contrib-uglify": "~5.0.1",
+        "grunt-contrib-uglify": "~5.1.0",
         "grunt-contrib-watch": "~1.1.0",
         "jslint": "^0.12.1",
         "less": "^4.1.1",