chore: release v0.4.0

[github-actions]

🤖 New release

• hugr: 0.4.0-alpha.1 -> 0.4.0 (⚠️ API breaking changes)

⚠️ hugr breaking changes

--- failure inherent_method_const_removed: pub method is no longer const ---

Description:
A publicly-visible method or associated fn is no longer `const` and can no longer be used in a `const` context.
        ref: https://doc.rust-lang.org/reference/const_eval.html
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.31.0/src/lints/inherent_method_const_removed.ron

Failed in:
  ConstF64::new in /tmp/.tmpZ2umbc/hugr/hugr/src/std_extensions/arithmetic/float_types.rs:43

--- failure struct_missing: pub struct removed or renamed ---

Description:
A publicly-visible struct cannot be imported by its prior path. A `pub use` may have been removed, or the struct itself may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.31.0/src/lints/struct_missing.ron

Failed in:
  struct hugr::ops::constant::ExtensionValue, previously in file /tmp/.tmpr3bjhk/hugr/src/ops/constant.rs:184

Changelog

0.4.0 (2024-05-20)

Bug Fixes

• Disallow non-finite values for ConstF64 (#1075)

Features

• Add verification to constant folding (#1030)
• Add Const::get_custom_value (#1037)
• Add serialization schema for metadata (#1038)

Refactor

• [breaking] Rename crate::ops::constant::ExtensionValue => OpaqueValue (#1036)

Testing

• Reorg OutlineCfg/nest_cfgs tests so hugr doesn't depend on algorithm (#1007)
• Ignore tests which depend on typetag when cfg(miri) (#1051)
• Really ignore tests which depend on typetag when cfg(miri) (#1058)
• Proptests for round trip serialisation of Types and Ops. (#981)

---

This PR was generated with release-plz.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.56%. Comparing base (51a253a) to head (e0ef0a1).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1031      +/-   ##
==========================================
- Coverage   86.60%   86.56%   -0.04%     
==========================================
  Files          83       83              
  Lines       17586    17586              
  Branches    17586    17586              
==========================================
- Hits        15230    15223       -7     
- Misses       1536     1543       +7     
  Partials      820      820              

Flag	Coverage Δ
rust	86.56% <ø> (-0.04%)	⬇️

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[aborgna-q]

Should we merge the pre-release notes with the final ones?

[aborgna-q]

I merged an unrelated PR to check what happened with this one.

release-plz notes that you made changes, so it recreated a new PR and closed this one to avoid conflicts.

I think the behaviour is OK, as we don't normally have that many PRs getting merged during a release.