fix(deps): update phpoffice/phpspreadsheet to 5.10

[AIlkiv]

Summary

• Raise phpoffice/phpspreadsheet from 5.7.0 to 5.10.0.
• The minimum constraint is now ^5.10, so the vulnerable 5.7–5.9 releases can no longer be installed.
• 5.10.0 patches the XmlScanner XXE/DoS issues (GHSA-rxj4-h86g-25gc, GHSA-3x94-m842-937c), the ODS row-repeat memory exhaustion (GHSA-j2w7-387v-m2rq), and the external-image SSRF whitelist bypass (GHSA-2phh-27fw-q4gc). These matter for spreadsheet import. https://github.com/nextcloud/tables/security/dependabot

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not needed
• 🔙 Backport requests are created or not needed: /backport to stableX.X
• 📅 Milestone is set
• 🌸 PR title is meaningful (if it should be in the changelog: is it meaningful to users?)

🤖 AI (if applicable)

• [ *] The content of this PR was partly or fully generated using AI