builder: correct uniqueItems and array types for non-body parameters

[Lfan-ke]

buildParameter set UniqueItems = !AllowMultiple() on every non-body parameter. But uniqueItems is an array-only validation in JSON Schema / OpenAPI, so:

• scalar query, path, header and form parameters (the overwhelming majority) were emitted with a spurious uniqueItems: true, and
• a parameter that does accept multiple values was still typed as a scalar instead of an array.

This corrects both the v2 (pkg/builder) and v3 (pkg/builder3) builders to:

• emit only {type, format} for scalar parameters (no uniqueItems);
• emit an array when the parameter allows multiple values - type: array + items (+ collectionFormat: multi in v2).

Unit tests cover both the scalar and the multi-value paths; the existing golden expectations are updated to drop the spurious uniqueItems.

Refs kubernetes/kubernetes#140050

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Lfan-ke / name: 林晨 (Leo Cheng) (5f770b1)

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