chore: release v0.3.0

[github-actions]

🤖 New release

• protobug: 0.2.1 -> 0.3.0 (⚠ API breaking changes)

⚠ protobug breaking changes

--- failure constructible_struct_adds_field: externally-constructible struct adds field ---

Description:
A pub struct constructible with a struct literal has a new pub field. Existing struct literals must be updated to include the new field.
        ref: https://doc.rust-lang.org/reference/expressions/struct-expr.html
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/constructible_struct_adds_field.ron

Failed in:
  field DisplayOptions.show_hex in /tmp/.tmpmD1cJ7/protobug/protobug/src/message.rs:53
  field DisplayOptions.show_ascii in /tmp/.tmpmD1cJ7/protobug/protobug/src/message.rs:54

Changelog

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