Update Rust crate handlebars to v5

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
handlebars	dependencies	major	4 -> 5

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Release Notes

sunng87/handlebars-rust (handlebars)

### [`v5.0.0`](https://togithub.com/sunng87/handlebars-rust/blob/HEAD/CHANGELOG.md#500---2023-12-31) [Compare Source](https://togithub.com/sunng87/handlebars-rust/compare/v4.5.0...v5.0.0) - \[Added] public mutable access to local variables in `BlockContext` \[[#​533](https://togithub.com/sunng87/handlebars-rust/issues/533)] - \[Changed] Simplified lifetime specifiers for `Helper`, `ScopedJson` and some other related types and functions. \[[#​532](https://togithub.com/sunng87/handlebars-rust/issues/532)] - \[Changed] Updated `TemplateError` to reduce its size. Direct field access is removed in favor of access methods - \[Changed] Introducing `RenderErrorReason` for typed render error - \[Changed] Changed `register_template_directory` api for more customizations \#\[610] - \[Changed] Updated rust-embed to 8.0

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