Update Rust crate heck to 0.4 - autoclosed

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
heck	dependencies	minor	0.3 -> 0.4

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Release Notes

withoutboats/heck

v0.4.0

Breaking changes:

• Make unicode support optional (off by default). Enable the unicode crate
  feature if you need unicode support.
• Rename all traits from SomeCase to ToSomeCase, matching stds convention
  of beginning trait names with a verb (ToOwned, AsRef, …)
• Rename ToMixedCase to ToLowerCamelCase
• Rename ToCamelCase to ToUpperCamelCase
• Add ToPascalCase as an alias to ToUpperCamelCase

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

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🔕 Ignore: Close this PR and you won't be reminded about this update again.

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