to force the file close or kill the process,
If Excel running on a different machine = some client, then it will be difficult to get & kill the process.
Remote PowerShell could be an option: https://adamtheautomator.com/how-to-kill-a-windows-process/
But again: Difficult.
My SQL job got failed because user who leaves the excel file open
And what is the SSIS job doing, juts reading the Excel file or ...?