Update version.h and HISTORY.md for the 6.24 release (#8688)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8688

Reviewed By: ajkr, riversand963

Differential Revision: D30467746

Pulled By: ltamasi

fbshipit-source-id: 0fce0d42fe2fe3cb56d7a89607154b3b957f09b6

HISTORY.md

@@ -1,5 +1,5 @@
 # Rocksdb Change Log
-## Unreleased
+## 6.24.0 (2021-08-20)
 ### Bug Fixes
 * If the primary's CURRENT file is missing or inaccessible, the secondary instance should not hang repeatedly trying to switch to a new MANIFEST. It should instead return the error code encountered while accessing the file.
 * Restoring backups with BackupEngine is now a logically atomic operation, so that if a restore operation is interrupted, DB::Open on it will fail. Using BackupEngineOptions::sync (default) ensures atomicity even in case of power loss or OS crash.

include/rocksdb/version.h

@@ -10,7 +10,7 @@
 #include "rocksdb/rocksdb_namespace.h"
 
 #define ROCKSDB_MAJOR 6
-#define ROCKSDB_MINOR 23
+#define ROCKSDB_MINOR 24
 #define ROCKSDB_PATCH 0
 
 // Do not use these. We made the mistake of declaring macros starting with