Rust: Generalize more models

[geoffw0]

Generalize more existing models to trait models. Follows on from #20652 and is covered by the same change note (assuming we merge soon enough).

[Copilot]

Pull Request Overview

This PR generalizes existing models in the Rust CodeQL library by converting specific implementations to trait-based models, improving their applicability across different types. This follows previous work in PR #20652.

Key changes:

• Converted implementation-specific models to trait models using <_ as Trait> notation
• Added a new iterator model for async operations
• Updated test expectations to reflect newly detected taint flows

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
rust/ql/test/library-tests/dataflow/sources/net/test.rs	Removed MISSING annotations indicating newly detected taint flows
rust/ql/test/library-tests/dataflow/sources/net/InlineFlow.expected	Updated test expectations with new model IDs and flow edges
rust/ql/lib/codeql/rust/frameworks/stdlib/net.model.yml	Generalized TcpStream read models to trait-based std::io::Read models
rust/ql/lib/codeql/rust/frameworks/stdlib/core.model.yml	Added trait model for async iterator next operation
rust/ql/lib/codeql/rust/frameworks/rustls.model.yml	Removed duplicate models now covered by generalized trait models
rust/ql/lib/codeql/rust/frameworks/mysql.model.yml	Generalized PooledConn models to trait-based Queryable models
rust/ql/lib/codeql/rust/frameworks/mysql-async.model.yml	Generalized Conn models to trait-based Queryable models
rust/ql/lib/codeql/rust/frameworks/futures.model.yml	Removed Box-specific iterator model and added generalized AsyncRead poll_read model

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[geoffw0]

I'm having a bit of difficulty with DCA runs failing, and I really do want to see the results for this PR. Please bare with me.