#25104 Fix property handling in OpenAPINormalizer

Fix OpenAPINormalizer to correctly handle required properties by splitting them into local and inherited lists

PR checklist

• Read the contribution guidelines.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

  (For Windows users, please run the script in WSL)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
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Summary by cubic

Fixes OpenAPINormalizer to correctly split required properties into local and inherited lists when refactoring allOf with properties. Required properties that exist on the schema stay with the child schema, while inherited required properties remain on the parent.