Upgrade pyxform and fix xls extension usage

[spwoodcock]

What type of PR is this? (check all applicable)

• 🍕 Feature
• 🐛 Bug Fix
• 📝 Documentation
• 🧑‍💻 Refactor
• ✅ Test
• 🤖 Build or CI
• ❓ Other (please specify)

Related Issue

Related to #1667

Describe this PR

• .xlsx was working fine, but .xls caused and error for some reason.
• Upgraded pyxform to latest, which has a much simpler convert function for XLSForm --> XForm.
• It attempts to parse XLSX and XLS in order, so we no longer need to pass through the form type.
• Upgrading also fixed the issue using .xls.

Checklist before requesting a review

• 📖 Read the FMTM Contributing Guide: https://github.com/hotosm/fmtm/blob/main/CONTRIBUTING.md
• 📖 Read the HOT Code of Conduct: https://docs.hotosm.org/code-of-conduct
• 👷‍♀️ Create small PRs. In most cases, this will be possible.
• ✅ Provide tests for your changes.
• 📝 Use descriptive commit messages.
• 📗 Update any related documentation and include any relevant screenshots.

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