Clarify the supported filesystems for Linux (neo4j#2122) (neo4j#2135)

Co-authored-by: Reneta Popova <[email protected]>

Author: NataliaIvakina

modules/ROOT/pages/installation/requirements.adoc

@@ -115,7 +115,8 @@ For more information on Red Hat Enterprise Linux Life Cycle, refer to their link
 
 For proper ACID behavior, the filesystem must support flush (_fsync_, _fdatasync_).
 Since databases can put a high and consistent load on a storage system for a long time, it is recommended to use a file system that has good aging characteristics.
-The EXT4 and XFS file systems are both supported.
+The EXT4 and XFS are the **only** supported file systems.
+
 See xref:performance/linux-file-system-tuning.adoc[Linux file system tuning] for details on how to configure the filesystem in Linux for optimal performance.