chore: upgrade examples to Rust 2024

[cibyr]

The missing use<> trait bounds confused the hell out of me trying to use some of the example code in a project using edition = "2024" so I thought I'd try and save others from the same fate.

For the sake of anyone searching, the error messages look like:

   Compiling browser-echo v0.1.0 (/home/cibyr/src/iroh-examples/browser-echo)
error[E0521]: borrowed data escapes outside of method
  --> src/wasm.rs:53:12
   |
47 |     pub fn connect(&self, node_id: String, payload: String) -> Result<JsReadableStream, JsError> {
   |                    -----
   |                    |
   |                    `self` is a reference that is only valid in the method body
   |                    let's call the lifetime of this reference `'1`
...
53 |         Ok(into_js_readable_stream(stream))
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |            |
   |            `self` escapes the method body here
   |            argument requires that `'1` must outlive `'static`

For more information about this error, try `rustc --explain E0521`.

Which didn't help me figure out that this was due to the changed lifetime capture rules in the 2024 edition, as applied to EchoNode::connect().

[matheus23]

Thank you this is very helpful!

[matheus23]

Cool stuff, TYVM!