Hardening proc macro path resolution broke cargo overrides

[alice-i-cecile]

This broke all my usages of bevy derive with messages like this:

error[E0433]: failed to resolve: use of undeclared crate or module `bevy_reflect`
   --> C:\Users\pcwal\Source\Rust\leafwing-input-manager\src\lib.rs:144:41
    |
144 | #[derive(Debug, Clone, Copy, PartialEq, Reflect, Serialize, Deserialize)]
    |                                         ^^^^^^^ use of undeclared crate or module `bevy_reflect`
    |
    = note: struct `crate::user_input::trait_reflection::tripleaxislike::TypeRegistration` exists but is inaccessible
    = note: this error originates in the derive macro `Reflect` (in Nightly builds, run with -Z macro-backtrace for more info)

and

error[E0277]: `user_input::gamepad::GamepadStick` can not provide dynamic type information through reflection
   --> C:\Users\pcwal\Source\Rust\leafwing-input-manager\src\user_input\gamepad.rs:548:23
    |
548 | impl DualAxislike for GamepadStick {
    |                       ^^^^^^^^^^^^ the trait `bevy::bevy_reflect::Typed` is not implemented for `user_input::gamepad::GamepadStick`

For reference, I'm using Cargo overrides to redirect Bevy 0.16.0 to the local repo.

Originally posted by @pcwalton in #17330 (comment)

[alice-i-cecile]

A reproduction is given in #17330 (comment).

@raldone01 has offered to try fixing this, but feel free to chime in and help out.

[raldone01]

I am trying to get the reproducer to work (It has some unrelated issues on my machine).
If anyone finds a simpler reproducer please comment here.

[raldone01]

Current state of my invenstigation:

The issue seems is caused by depending on bevy in dev and normal dependencies:

[dependencies]
bevy.workspace = true
[dev-dependencies]
bevy.workspace = true

The error of the cargo-manifest-proc-macros crate was being ignored in BevyManifest:

    /// Returns the path for the crate with the given name.
    pub fn get_path(&self, name: &str) -> syn::Path {
        self.maybe_get_path(name)
            .expect("Failed to get path for crate")
        // Moving the comment here shows the error
        //.unwrap_or_else(|_err| Self::parse_str(name))
    }

The ambiguity detection in cargo-manifest-proc-macros detects false positives. I am working on a fix as I am the author. I already have a failing test that covers the scenario in bevy.