[java][spring] fix: disableDiscriminatorJsonIgnoreProperties not working

[knikolos]

Config option disableDiscriminatorJsonIgnoreProperties added in #22528 and documented here https://github.com/dnowo/openapi-generator/blob/0691dc80373076b0409d688774efe5ab7204e44d/docs/generators/spring.md?plain=1#L45 was not taken in account during generation, this PR fixes that.

@cachescrubber (2022/02) @welshm (2022/02) @MelleD (2022/02) @atextor (2022/02) @manedev79 (2022/02) @javisst (2022/02) @borsch (2022/02) @banlevente (2022/02) @Zomzog (2022/09) @martin-mfg (2023/08)

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[cubic-dev-ai]

No issues found across 2 files