[BUG][Python][Generator] Setting package name with dash propagates to generated code without replacing dash with underscore

Description

Try to generate any python schema with --package-name <some name with dash>, and you should see the issue. The detrimental side of this issue is that dashes are not valid in module imports:

import my-api-client

This is bad. We want:

import my_api_client

openapi-generator version

openapi-generator-cli 7.1.0
commit : unknown
built : -999999999-01-01T00:00:00+18:00
source : https://github.com/openapitools/openapi-generator
docs : https://openapi-generator.tech

OpenAPI declaration file content or url

Try with this, note the problem is schema independent:

openapi: "3.0.0"
info:
  version: 1.0.0
  title: service1
  description: Service description
  contact:
    name: Maintainer name
    email: Maintainer email
servers:
  - url: service1.company.com
paths:
  /path/to/api:
    get:
      summary: sample handler
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Resp'
components:
  schemas:
    Resp:
      type: object
      properties:
        prop1:
          type: string
        prop2:
          type: string
      required:
        - prop2

Generation Details

openapi-generator generate \
        --generator-name python \
        --input-spec openapi.yaml \
        --package-name {{ name with underscore!! }} \
        --additional-properties=packageVersion=$(poetry version -s)

Current workaround, run this after generation:

sed -i 's/name = {{ name with underscore!! }}/name = {{ name with dash!! }}/' {{ api_gen_dir }}/pyproject.toml

Reproduce the problem with the minimal OpenAPI YAML and the supplied Python generator command using a dashed package name. Inspect the generated Python imports and package files, then verify that generated module references use underscores while the package metadata remains correct.