fix: Use "demande" instead of "requête" in French translation

[marien-probesys]

Related issue(s)

N/A

How to test manually

1. Create a request
2. Make sure the interface is in French
3. In the list of tickets, verify that the ticket is indicated as "Demande ouverte le..."

Checklist

• Code is manually tested
• Permissions / authorizations are verified
• New data can be imported
• Interface works on both mobiles and big screens
• Interface works in both light and dark modes
• Interface works on both Firefox and Chrome
• Accessibility has been tested
• Translations are synchronized
• Tests are up to date
• Copyright notices are up to date
• Documentation is up to date
• Pull request has been reviewed and approved