chore(deps): update dependency java to v21 (#4688)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

clients/algoliasearch-client-java/.java-version

@@ -1 +1 @@
-17.0.14+7
+21.0.6+7.0.LTS