Bump hppc from 0.8.1 to 0.9.1 in /server

Bumps [hppc](https://github.com/carrotsearch/hppc) from 0.8.1 to 0.9.1.
- [Release notes](https://github.com/carrotsearch/hppc/releases)
- [Changelog](https://github.com/carrotsearch/hppc/blob/master/CHANGES.txt)
- [Commits](carrotsearch/hppc@0.8.1...0.9.1)

---
updated-dependencies:
- dependency-name: com.carrotsearch:hppc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

server/build.gradle

@@ -113,7 +113,7 @@ dependencies {
 
   // utilities
   api project(":libs:opensearch-cli")
-  api 'com.carrotsearch:hppc:0.8.1'
+  api 'com.carrotsearch:hppc:0.9.1'
 
   // time handling, remove with java 8 time
   api "joda-time:joda-time:${versions.joda}"