chore(deps): bump fast-xml-parser and @astrojs/rss

Bumps [fast-xml-parser](https://github.com/NaturalIntelligence/fast-xml-parser) to 5.5.11 and updates ancestor dependency [@astrojs/rss](https://github.com/withastro/astro/tree/HEAD/packages/astro-rss). These dependencies need to be updated together.


Updates `fast-xml-parser` from 5.4.1 to 5.5.11
- [Release notes](https://github.com/NaturalIntelligence/fast-xml-parser/releases)
- [Changelog](https://github.com/NaturalIntelligence/fast-xml-parser/blob/master/CHANGELOG.md)
- [Commits](https://github.com/NaturalIntelligence/fast-xml-parser/commits)

Updates `@astrojs/rss` from 4.0.17 to 4.0.18
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/astro-rss/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/@astrojs/rss@4.0.18/packages/astro-rss)

---
updated-dependencies:
- dependency-name: fast-xml-parser
  dependency-version: 5.5.11
  dependency-type: indirect
- dependency-name: "@astrojs/rss"
  dependency-version: 4.0.18
  dependency-type: direct:development
...

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Author: dependabot[bot]

package-lock.json

@@ -21,7 +21,7 @@
   },
   "devDependencies": {
     "@astrojs/mdx": "^5.0.2",
-    "@astrojs/rss": "^4.0.17",
+    "@astrojs/rss": "^4.0.18",
     "@astrojs/sitemap": "^3.7.1",
     "@eslint/js": "^9.29.0",
     "@tailwindcss/typography": "^0.5.19",