XLSX ingestion: integers are converted to decimal numbers

Bug description

This follows a discussion in the Google Group Dataverse:
https://groups.google.com/g/dataverse-community/c/75OO7gDNpsw/

When ingesting an XLSX file, any non-zero numeric value is always interpreted as a decimal number.
This results in integers being automatically converted into decimals:

• 2 → 2.0
• -2 → -2.0
• 2.5 → 2.5

This behavior can be problematic in some use cases (e.g., phone numbers, street numbers).

Notes:

• This issue does not occur when ingesting a CSV file, where integers remain integers.
• Reproducible example dataset: test dataset.

Steps to reproduce

1. Create an XLSX file containing a column with integer values.
2. Ingest into Dataverse.
3. Observe that all integers are converted into decimals.

Expected behavior

• Keep integers as integers during ingestion unless a decimal value is explicitly present.
  • 2 → 2
  • -2 → -2
  • 2.5 → 2.5

Impact

• Incorrect data representation in business contexts.
• Inconsistency between XLSX ingestion and CSV ingestion.

Affected versions

• All versions of Dataverse

Help is always welcome, is this bug something you or your organization plan to fix?

• This is not currently planned by the team.