build(deps): update indexmap requirement from ~2.11.4 to ~2.12.1

[dependabot]

Updates the requirements on indexmap to permit the latest version.

Changelog

Sourced from indexmap's changelog.

2.12.1 (2025-11-20)

• Simplified a lot of internals using hashbrown's new bucket API.

2.12.0 (2025-10-17)

• MSRV: Rust 1.82.0 or later is now required.
• Updated the hashbrown dependency to 0.16 alone.
• Error types now implement core::error::Error.
• Added pop_if methods to IndexMap and IndexSet, similar to the method for Vec added in Rust 1.86.

2.11.4 (2025-09-18)

• Updated the hashbrown dependency to a range allowing 0.15 or 0.16.

2.11.3 (2025-09-15)

• Make the minimum serde version only apply when "serde" is enabled.

2.11.2 (2025-09-15)

• Switched the "serde" feature to depend on serde_core, improving build parallelism in cases where other dependents have enabled "serde/derive".

2.11.1 (2025-09-08)

• Added a get_key_value_mut method to IndexMap.
• Removed the unnecessary Ord bound on insert_sorted_by methods.

2.11.0 (2025-08-22)

• Added insert_sorted_by and insert_sorted_by_key methods to IndexMap, IndexSet, and VacantEntry, like customizable versions of insert_sorted.
• Added is_sorted, is_sorted_by, and is_sorted_by_key methods to IndexMap and IndexSet, as well as their Slice counterparts.
• Added sort_by_key and sort_unstable_by_key methods to IndexMap and IndexSet, as well as parallel counterparts.
• Added replace_index methods to IndexMap, IndexSet, and VacantEntry to replace the key (or set value) at a given index.
• Added optional sval serialization support.

2.10.0 (2025-06-26)

• Added extract_if methods to IndexMap and IndexSet, similar to the methods for HashMap and HashSet with ranges like Vec::extract_if.
• Added more #[track_caller] annotations to functions that may panic.

2.9.0 (2025-04-04)

... (truncated)

Commits

• cfad758 Merge pull request #424 from cuviper/buckets
• a96b9c7 Release 2.12.1
• 6245ee5 Use the bucket API from hashbrown v0.16.1
• 0e68f8a Merge pull request #422 from cuviper/msrv-1.82
• 61c9c94 ci: only run full miri in the merge queue
• db43f19 Release 2.12.0
• b46a32a Move more to the lints table
• 4849b16 Make use of RFC2145 type privacy for sealed traits
• cfff4b7 Use bounds in associated type position
• c7178d7 Use core::error::Error
• Additional commits viewable in compare view

Most Recent Ignore Conditions Applied to This Pull Request

Dependency Name	Ignore Conditions
indexmap	[>= 1.9.a, < 1.10]

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[dependabot]

Superseded by #96.