Bump grunt

Bumps the npm_and_yarn group with 1 update in the /h2o-docs-theme directory: [grunt](https://github.com/gruntjs/grunt).


Updates `grunt` from 0.4.5 to 1.6.1
- [Release notes](https://github.com/gruntjs/grunt/releases)
- [Changelog](https://github.com/gruntjs/grunt/blob/main/CHANGELOG)
- [Commits](gruntjs/grunt@v0.4.5...v1.6.1)

---
updated-dependencies:
- dependency-name: grunt
  dependency-type: direct:development
  dependency-group: npm_and_yarn
...

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

h2o-docs-theme/package.json

@@ -4,7 +4,7 @@
   "private": true,
   "dependencies": {},
   "devDependencies": {
-    "grunt": "~0.4.1",
+    "grunt": "~1.6.1",
     "grunt-contrib-sass": "~0.7.2",
     "grunt-contrib-watch": "~0.4.3",
     "grunt-contrib-connect": "0.5.0",