chore(Cargo.toml): prepare v0.4.0

[mxinden]

No description provided.

[Copilot]

Pull request overview

Prepares the crate for the v0.4.0 release by bumping the package version in Cargo metadata, keeping Cargo.toml and Cargo.lock in sync.

Changes:

• Bump crate version from 0.3.0 to 0.4.0 in Cargo.toml.
• Update the happy-eyeballs entry in Cargo.lock to 0.4.0.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
Cargo.toml	Updates the crate’s published package version to 0.4.0.
Cargo.lock	Aligns the lockfile’s happy-eyeballs package version with the new release version.

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.72%. Comparing base (0889699) to head (e86759c).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #61   +/-   ##
=======================================
  Coverage   88.72%   88.72%           
=======================================
  Files           2        2           
  Lines         754      754           
  Branches      754      754           
=======================================
  Hits          669      669           
  Misses         77       77           
  Partials        8        8           

Flag	Coverage Δ
linux	88.72% <ø> (ø)

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