Validate the information provided by SR2025 signups

[PeterJCLaw]

During SR2024 we had a couple of cases where the phone numbers provided for team supervisors were to their institution landline rather than being a direct way to contact the person at an event. We should at least do a basic check that the numbers look like mobile numbers.

We should also sanity check any other details we're asking for to ensure that they're useful to us.

Follows from srobo/runbook#204

[samjmartin04]

Worth noting that some institutions that have signed up with their landline number may not know the mobile number that they will have during the competition weekend at this stage

[PeterJCLaw]

Thus far we have:

• four teams where the primary contact's phone number doesn't look like a mobile number
• one team where there is no secondary contact mobile number

[PeterJCLaw]

Have sent emails to the teams without a mobile number. Holding off on the missing secondary contact phone number until we've done #1467.

[PeterJCLaw]

All have been chased and provided alternatives or reasons why they can't.