chore(deps): bump org.litote.kmongo:kmongo in /backend/persistence

Bumps [org.litote.kmongo:kmongo](https://github.com/Litote/kmongo) from 5.2.1 to 5.5.1.
- [Release notes](https://github.com/Litote/kmongo/releases)
- [Commits](Litote/kmongo@kmongo-5.2.1...kmongo-5.5.1)

---
updated-dependencies:
- dependency-name: org.litote.kmongo:kmongo
  dependency-version: 5.5.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/persistence/build.gradle

@@ -30,5 +30,5 @@ description = 'DevFeed Persistence APIs'
 dependencies {
     api project(':dev-feed-common')
     implementation 'com.fasterxml.jackson.core:jackson-databind:2.19.2'
-    implementation 'org.litote.kmongo:kmongo:5.2.1'
+    implementation 'org.litote.kmongo:kmongo:5.5.1'
 }