lavu/version: fix minor version

The latest version should be 59.18.100 since commit 01c5f4ad

$ git diff 01c5f4ad~1..HEAD doc/APIchanges
...
+2024-05-10 - xxxxxxxxx - lavu 59.18.100 - cpu.h
+  Add AV_CPU_FLAG_RV_ZVBB.
+
Signed-off-by: Haihao Xiang <haihao.xiang@intel.com>

libavutil/version.h

@@ -79,7 +79,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  59
-#define LIBAVUTIL_VERSION_MINOR  17
+#define LIBAVUTIL_VERSION_MINOR  18
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \