Changed clippy.toml and added std hashmap and hashset to disallowed t…

[Phaneendra293]

• Closes Consider disallowing std hashmap/hashset via clippy #19869

This PR updates the Clippy configuration to disallow usage of std::collections::HashMap and std::collections::HashSet across the DataFusion codebase.

The change helps enforce consistent usage of project-preferred HashMap/set implementations, avoiding accidental use of the standard library types.

What changed

Updated clippy. toml to add std::collections::HashMap and std::collections::HashSet to the list of disallowed types.

Ensures new code follows the project’s hashing and performance conventions.

Why

The default Rust HashMap / HashSet use randomized hashing, which may be:

non-deterministic,

sub-optimal for performance-critical paths,

inconsistent with DataFusion’s existing design choices.

Enforcing this at the lint level prevents regressions and improves code consistency for contributors.

Testing

No functional code changes.

CI / Clippy will fail if std::HashMap or std::HashSet are newly introduced.

[Phaneendra293]

The changes have been completed and pushed.
Kindly review and let me know if there are any additional modifications required.

[Jefffrey]

Thanks for volunteering to pick up this issue; part of the expectation of the issue is to ensure CI passes, namely that clippy violations are fixed. Could you look into this please?

[alamb]

Looks like there are clippy failures now -- can you fix them @Phaneendra293 ?