Bump next-sitemap from 1.4.19 to 1.5.2

Bumps [next-sitemap](https://github.com/iamvishnusankar/next-sitemap) from 1.4.19 to 1.5.2.
- [Release notes](https://github.com/iamvishnusankar/next-sitemap/releases)
- [Commits](iamvishnusankar/next-sitemap@v1.4.19...v1.5.2)

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

Author: dependabot[bot]

package-lock.json

@@ -66,7 +66,7 @@
     "graphql-anywhere": "^4.2.7",
     "hamburger-react": "^2.4.0",
     "next-seo": "^4.19.0",
-    "next-sitemap": "^1.4.19",
+    "next-sitemap": "^1.5.2",
     "postcss": "^7.0.35",
     "postcss-flexbugs-fixes": "^4.2.1",
     "postcss-preset-env": "^6.7.0",