Fix `Vec<Vec<u8>>` and `std::backtrace::Backtrace`

[fzyzcjy]

Without the fix, it errors like:

(base) ➜  allo-isolate git:(master) ✗ cargo test
warning: file `/Volumes/MyExternal/ExternalRefCode/allo-isolate/tests/containers.rs` found to be present in multiple build targets:
  * `example` target `containers`
  * `integration-test` target `containers`
   Compiling allo-isolate v0.1.23 (/Volumes/MyExternal/ExternalRefCode/allo-isolate)
error[E0277]: the trait bound `Vec<Vec<u8>>: IntoDart` is not satisfied
   --> tests/containers.rs:227:26
    |
227 |     assert!(isolate.post(vec![vec![10u8]]));
    |                     ---- ^^^^^^^^^^^^^^^^ the trait `IntoDart` is not implemented for `Vec<Vec<u8>>`
    |                     |
    |                     required by a bound introduced by this call
    |
    = help: the following other types implement trait `IntoDart`:
              Vec<i8>
              Vec<i16>
              Vec<i32>
              Vec<i64>
              Vec<u8>
              Vec<u16>
              Vec<u32>
              Vec<u64>
            and 3 others
note: required by a bound in `Isolate::post`
   --> /Volumes/MyExternal/ExternalRefCode/allo-isolate/src/lib.rs:133:34
    |
133 |     pub fn post(&self, msg: impl IntoDart) -> bool {
    |                                  ^^^^^^^^ required by this bound in `Isolate::post`

For more information about this error, try `rustc --explain E0277`.
error: could not compile `allo-isolate` (test "containers") due to previous error
warning: build failed, waiting for other jobs to finish...
(base) ➜  allo-isolate git:(master) ✗ 

[fzyzcjy]

You are welcome! Looking forward to next release

[fzyzcjy]

So I wonder when will the next release be 👀

[shekohex]

Hey, sorry I did miss that. Will do a release shortly.

[fzyzcjy]

It's OK, take your time!

[shekohex]

Released under v0.1.24