feat(anyspawn): allow creating spawner using tokio handle

[martintmk]

Enables explicitly passing tokio handle when creating Spawner. Used for scenarios where tokio runtime is explicitly created and then spawning is done through Spawner even from places where Tokio context is not initialized on the thread (interop).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.0%. Comparing base (8b9c195) to head (8f6c540).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #341   +/-   ##
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  Coverage   100.0%   100.0%           
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  Files         210      210           
  Lines       15540    15553   +13     
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+ Hits        15540    15553   +13     

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[Copilot]

Pull request overview

Adds support in anyspawn for constructing spawners/builders with an explicit tokio::runtime::Handle, enabling task spawning from threads without an ambient Tokio runtime context (interop scenarios).

Changes:

• Extend Spawner’s Tokio implementation to optionally store a tokio::runtime::Handle and use it for spawning when provided.
• Add Spawner::new_tokio_with_handle and CustomSpawnerBuilder::tokio_with_handle constructors.
• Update crate docs/feature lists (including README content) to mention the new constructor(s).

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 5 comments.

File	Description
crates/anyspawn/src/spawner.rs	Store optional Tokio Handle in the Tokio spawner kind and add new_tokio_with_handle; spawn via handle when present.
crates/anyspawn/src/builder.rs	Add CustomSpawnerBuilder::tokio_with_handle to build custom spawners backed by a provided Tokio handle.
crates/anyspawn/src/lib.rs	Update feature documentation to mention the new Tokio-handle constructor.
crates/anyspawn/README.md	Update generated README feature list/links to reference the new constructor.

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated no new comments.

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