chore(deps): bump sharp from 0.32.1 to 0.32.6 in /packages/backend

Bumps [sharp](https://github.com/lovell/sharp) from 0.32.1 to 0.32.6.
- [Release notes](https://github.com/lovell/sharp/releases)
- [Changelog](https://github.com/lovell/sharp/blob/main/docs/changelog.md)
- [Commits](lovell/sharp@v0.32.1...v0.32.6)

---
updated-dependencies:
- dependency-name: sharp
  dependency-type: direct:production
...

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

packages/backend/package.json

@@ -29,7 +29,7 @@
     "polka": "1.0.0-next.22",
     "rate-limiter-flexible": "2.4.1",
     "shared": "link:../shared",
-    "sharp": "0.32.1",
+    "sharp": "0.32.6",
     "shikiji": "^0.9.14",
     "sirv": "2.0.3",
     "toml": "3.0.0",