Fix error when exporting all records

[perryfaro]

If you choose 'all' in the filament table and then select one or more rows for export, you will receive the following error message:

Unsupported operand types: string * int

With this fix, at the time of export, in the case of the 'all' option, it calculates the number of records in the collection to prevent the error.

[alperenersoy]

hey! sorry but could not recreate the problem. as I see it defines tableRecordsPerPage as -1 when I select All. which exact version of filament are you using?

[Manoah1988]

Same problem, and i fix with your code @perryfaro Thank you so much!