Replace lazy_static with once_cell

[daxpedda]

This replaces lazy_static with once_cell. Couple of reasons:

• The ecosystem in general is shifting away from lazy_static to once_cell, so hopefully one day we can eliminate lazy_static from the dependency tree.
• lazy_static is unmaintained.
• once_cell is much closer to whats going to be stabilized in Rust v1.70 and future versions: Tracking Issue for once_cell rust-lang/rust#74465.

[sfackler]

The macos build is failing (ignore the Linux one, I will fix that).

[daxpedda]

Done. Thank you for pinging.

[sfackler]

error[E0432]: unresolved import `self::once_cell::Lazy`
  --> src/imp/security_framework.rs:25:5
   |
25 | use self::once_cell::Lazy;
   |     ^^^^^^^^^^^^^^^^^^^^^ no `Lazy` in the root

[daxpedda]

Apologies, that was pretty lazy of me.
I tried it out locally now.