Fix 64-bit atomic operations on 32-bit machines (#19531)
Fix 64-bit atomic operations on 32-bit machines (#19531)

- Doing 64-bit atomic operations on 32-bit machines is a bit tricky by
golang, as they can only be done under certain set of
conditions(https://pkg.go.dev/sync/atomic#pkg-note-BUG).
- This PR fixes such case whereby the conditions weren't met, it moves
the int64 to the first field of the struct, which will 64-bit operations
happening on this property on 32-bit machines.
- Resolves #19518
go-gitea/gitea,go-gitea/gitea,go-gitea/gitea