Fix failing proc macros when depending on bevy through dev and normal dependencies.

[raldone01]

This is a follow up fix for #17330 and fixes #17780.
There was a logic error in the ambiguity detection of cargo-manifest-proc-macros.
cargo-manifest-proc-macros now has a test for this case to prevent the issue in the future.

I also opted to hard fail if the cargo-manifest-proc-macros crate fails. That way the error is more obvious and easier to fix and diagnose.

Testing

• The reproducer: Migrate bevy to latest main bevy_editor_prototypes#178 works for me using these fixes.

[villor]

I can confirm that this fixes the issues encountered in bevyengine/bevy_editor_prototypes#178
Using this PR in place of bevy main, the code compiles with no errors.

[alice-i-cecile]

Fantastic; thank you so much for the prompt investigation and fix! The upstream fix was particularly nice :)