In the async VFS, treat the new error code SQLITE_IOERR_DELETE_NOENT as success for xDelete.

FossilOrigin-Name: c507ca4a8eb255923ff32001a1903dc85960f485
diff --git a/ext/async/sqlite3async.c b/ext/async/sqlite3async.c
index 0814da7..4ab39ca 100644
--- a/ext/async/sqlite3async.c
+++ b/ext/async/sqlite3async.c
@@ -1510,6 +1510,7 @@
       case ASYNC_DELETE:
         ASYNC_TRACE(("DELETE %s\n", p->zBuf));
         rc = pVfs->xDelete(pVfs, p->zBuf, (int)p->iOffset);
+        if( rc==SQLITE_IOERR_DELETE_NOENT ) rc = SQLITE_OK;
         break;
 
       case ASYNC_OPENEXCLUSIVE: {