Remove `unsafe` impls

[code-dogg]

The goal is to eliminate unsafe impls

op-move/server/src/dependency/in_memory.rs

Line 16 in bf4852e

unsafe impl Sync for InMemoryDependencies {}

op-move/app/src/dependency.rs

Line 24 in bf4852e

unsafe impl<'app, D: Dependencies<'app>> Sync for ApplicationReader<'app, D> {}