fix(gpu): force uint64 when calculating lwe chunksize

[guillermo-oyarzun]

closes: please link all relevant issues

PR content/description

Check-list:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• Relevant issues are marked as resolved/closed, related issues are linked in the description
• Check for breaking changes (including serialization changes) and add them to commit message following the conventional commit specification

[guillermo-oyarzun]

I added the info in the panic message so no capture is not needed.

[agnesLeroy]

🙏