BLD: Set scipy latest supported version to 1.14

[rrjbca]

Description

Set scipy latest supported version to 1.14

Checklist

• [x] Follow the Contributor Guidelines
• [ ] Write unit tests
• [ ] Write documentation strings
• [ ] Assign someone from your working team to review this pull request
• [x] Assign someone from the infrastructure team to review this pull request

[rrjbca]

Depends on an update to speclite supporting scipy 1.14; see https://github.com/desihub/speclite/pull/87