fix: OpenBSD

[dignifiedquire]

Using

> cargo test --no-default-features

most tests now pass on OpenBSD

• patches a fixed version of iroh@0.4
• introduce compile time flag to disable sqlcipher

Closes #5552

[dignifiedquire]

Reverted the part of making sqlcipher optional, as this seems only a linking issue for at this point.

Vendoring won't work, so need to make the non vendored version work

[link2xt]

I think this is fixed on iroh side, so can be closed?

[dignifiedquire]

I think this is fixed on iroh side, so can be closed?

For the main branch and current releases, yes, backporting to 0.4 got complicated.

[link2xt]

Ok, let's close this PR and get rid of 0.4 instead.