Fix `AutomaticSpeechRecognitionPipelineTests.run_pipeline_test`
# What does this PR do?

Fix `AutomaticSpeechRecognitionPipelineTests.run_pipeline_test` which was changed in #19570 and #20104.

See the comments in this PR changes.

I detected this when working on improving pipeline tests using tiny models. Previously, `Speech2TextConfig` is not used in ASR pipeline tests, but now it does, and  gives errors without this PR.
_The documentation is not available anymore as the PR was closed or merged._<|||||>Thank you !