Latest redb forces rust edition 2024

[b5]

Makes tutorials painful if folks aren't running the bleeding edge rust & they pull in blobs.

We should pin to a redb version that adheres to the Iroh MSRV, or bump the whole thing up, which I'm not a fan of.

[dignifiedquire]

should restrict the version to < 2.5

[rklaehn]

#88

[rklaehn]

Reduced the redb version in the new blobs. This is becoming a major annoyance since crates all over the ecosystem go to 2024...