pin e-h alpha

[jacobrosenthal]

Alphas dont follow semver and theres a new e-h alpha now which has breaking changes and is automatically being picked up in 10.0.

Obviously can update for the new e-h hal alpha as well, but seems best to get this patch and a new 10.1 release in first.

error[E0107]: this trait takes 0 generic arguments but 1 generic argument was supplied
  --> /home/jacob/.cargo/registry/src/github.com-1ecc6299db9ec823/radio-0.10.0/src/blocking.rs:97:30
   |
97 |     T: Transmit<Error = E> + DelayUs<u32>,
   |                              ^^^^^^^----- help: remove these generics
   |                              |
   |                              expected 0 generic arguments
   |
note: trait defined here, with 0 generic parameters
  --> /home/jacob/.cargo/registry/src/github.com-1ecc6299db9ec823/embedded-hal-1.0.0-alpha.6/src/delay.rs:14:15
   |
14 |     pub trait DelayUs {
   |               ^^^^^^^

error[E0107]: this trait takes 0 generic arguments but 1 generic argument was supplied
   --> /home/jacob/.cargo/registry/src/github.com-1ecc6299db9ec823/radio-0.10.0/src/blocking.rs:180:39
    |
180 |     T: Receive<Info = I, Error = E> + DelayUs<u32>,
    |                                       ^^^^^^^----- help: remove these generics
    |                                       |
    |                                       expected 0 generic arguments
    |
note: trait defined here, with 0 generic parameters
   --> /home/jacob/.cargo/registry/src/github.com-1ecc6299db9ec823/embedded-hal-1.0.0-alpha.6/src/delay.rs:14:15
    |
14  |     pub trait DelayUs {
    |               ^^^^^^^

error[E0107]: this trait takes 0 generic arguments but 1 generic argument was supplied
   --> /home/jacob/.cargo/registry/src/github.com-1ecc6299db9ec823/radio-0.10.0/src/blocking.rs:223:38
    |
223 |     T: State<State = S, Error = E> + DelayUs<u32>,
    |                                      ^^^^^^^----- help: remove these generics
    |                                      |
    |                                      expected 0 generic arguments
    |
note: trait defined here, with 0 generic parameters
   --> /home/jacob/.cargo/registry/src/github.com-1ecc6299db9ec823/embedded-hal-1.0.0-alpha.6/src/delay.rs:14:15
    |
14  |     pub trait DelayUs {
    |               ^^^^^^^

For more information about this error, try `rustc --explain E0107`.
error: could not compile `radio` due to 3 previous errors
warning: build failed, waiting for other jobs to finish...
error: build failed

[ryankurte]

hey thanks for the PR! the reason i didn't have this is that it means we can slide over alpha releases so long as they're not breaking for us (and you can pin the version at the project level), but, given this release has broken our API it seems like a good addition for now ^_^