Fixes for redpanda against seastar 24.2.x

[graphcareful]

This PR includes all of the changes necessary to build redpanda against the seastar 24.2.x branch

Backports Required

• [x] none - not a bug fix
• [ ] none - this is a backport
• [ ] none - issue does not exist in previous branches
• [ ] none - papercut/not impactful enough to backport
• [ ] v23.3.x
• [ ] v23.2.x

Release Notes

• none