Add SQLite version 3.31.1

Author: resilar

rekeyvacuum.c

@@ -8,7 +8,7 @@
 ** Change 2: Remove local variable 'int nRes'
 ** Change 3: Remove initialization 'nRes = sqlite3BtreeGetOptimalReserve(pMain)'
 **
-** Code generated by script/rekeyvacuum.sh from SQLite v3.30.1 amalgamation.
+** Code generated by script/rekeyvacuum.sh from SQLite v3.31.1 amalgamation.
 */
 SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3RekeyVacuum(
   char **pzErrMsg,        /* Write error message here */