tapdb: add SQLITE_BUSY_SNAPSHOT err code to re-tryable errors

During a trace run we noticed that sometimes there's a conflict in
transactions that return the (517) SQLITE_BUSY_SNAPSHOT error code.
See https://www.sqlite.org/rescode.html#busy_snapshot.

We add this error to the list of re-tryable errors so the database
transaction re-try mechanism will simply try again.

Author: guggero

tapdb/sqlerrors.go

@@ -55,7 +55,7 @@ func parseSqliteError(sqliteErr *sqlite.Error) error {
 
 	// A write operation could not continue because of a conflict within the
 	// same database connection.
-	case sqlite3.SQLITE_LOCKED:
+	case sqlite3.SQLITE_LOCKED, sqlite3.SQLITE_BUSY_SNAPSHOT:
 		return &ErrDeadlockError{
 			DbError: sqliteErr,
 		}