[BUG] [dart-dio] Support for Analyzer configuration options changes in Dart 3

[souta0104]

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?
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Description

Analyzer configuration options changed in Dart 3, removing the implicit-casts and implicit-dynamic options.
https://dart.dev/resources/dart-3-migration#analyzer-config

If you are using Dart 3 and have specified these options in analysis_options.yaml, running the flutter analyze command will be treated as a warning.

The analysis_options.yaml in the Dart code generated by openapi-generator contains these options, so you need to migrate and fix it so that it does not contain these options.

openapi-generator version

6.4.0

Related issues/PRs

It could not be discovered on its own.

Suggest a fix

I am not familiar with the openapi-generator implementation, so this is inaccurate, but you should probably just modify the code in this section according to the migration guide.
https:// dart.dev/resources/dart-3-migration#analyzer-config

openapi-generator/modules/openapi-generator/src/main/resources/dart/libraries/dio/analysis_options.mustache

Lines 5 to 7 in b4eb9a4

	strong-mode:
	implicit-dynamic: false
	implicit-casts: false

[souta0104]

It was resolved. thank you.