Start release 7.5 development (#10204)

Summary:
Update HISTORY.md and version.h

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10204

Test Plan: version bump only

Reviewed By: ajkr

Differential Revision: D37271866

Pulled By: pdillinger

fbshipit-source-id: 0ccaa2af36648a5b6017c172a7826a244e1aec93

HISTORY.md

@@ -1,4 +1,6 @@
 # Rocksdb Change Log
+## Unreleased
+
 ## 7.4.0 (06/19/2022)
 ### Bug Fixes
 * Fixed a bug in calculating key-value integrity protection for users of in-place memtable updates. In particular, the affected users would be those who configure `protection_bytes_per_key > 0` on `WriteBatch` or `WriteOptions`, and configure `inplace_callback != nullptr`.

include/rocksdb/version.h

@@ -12,7 +12,7 @@
 // NOTE: in 'main' development branch, this should be the *next*
 // minor or major version number planned for release.
 #define ROCKSDB_MAJOR 7
-#define ROCKSDB_MINOR 4
+#define ROCKSDB_MINOR 5
 #define ROCKSDB_PATCH 0
 
 // Do not use these. We made the mistake of declaring macros starting with