[BUG][rust-reqwest] Explode param is not handled

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Even if openapi specs is

explode: true

Params value is sent has a comma delimited value param=value1,value2, should be param=value1&param=value2

openapi-generator version

5.3.0

OpenAPI declaration file content or url

  parameters:
    - name: tags
      in: query
      description: Tags to filter by
      required: true
      style: form
      explode: true
      schema:
        type: array
        items:
          type: string

Generation Details

$ ./bin/generate-samples.sh ./bin/configs/rust-reqwest-petstore-explode.yaml

$ cat ./samples/client/petstore/rust/reqwest/petstore-explode/src/apis/pet_api.rs |grep tags

Steps to reproduce

Related issues/PRs

Suggest a fix

Start with bin/configs/rust-reqwest-petstore-explode.yaml and generate the sample using bin/generate-samples.sh. Inspect samples/client/petstore/rust/reqwest/petstore-explode/src/apis/pet_api.rs, focusing on serialization of the tags query parameter. Done means explode: true produces repeated query parameters such as tags=value1&tags=value2 rather than a comma-delimited value.