While not being mentioned in our documentation, based on Microsoft KB, it should be possible to monitor via File System auditing.
The file-system folder where SSIS packages reside could be audited (if File System Auditing License is present) for changes to the file-system contents.
Auditing MSDB SYSSSISPackages table with traditional SQL Auditing can allow audit for SQL:StmtStarting/SQL:StmtCompleted (or similar) SQL audit events for queries potentially touching that table. Experimentation/testing would be required.
SQL DLA Auditing does not support auditing of System Databases so cannot be used for this purpose.