[kotlin] Invoke reified function with explicit type

[ffffionn]

Specify the class/type when calling the reified generic function parseDateToQueryString in the Kotlin client generator.
Fixes #23486

Tagging Kotlin technical committee
@karismann @Zomzog @andrewemery @4brunu @yutaka0m @stefankoppier @e5l @dennisameling

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Summary by cubic

Ensure Kotlin client generators and samples call the reified parseDateToQueryString with explicit type arguments for date/time query params to prevent compile errors in generated clients. Fixes #23486.

• Bug Fixes
  • Generate parseDateToQueryString<...>(...) for date/time query params in jvm-okhttp, jvm-spring-restclient, jvm-spring-webclient, and jvm-vertx.
  • Update ApiClient.kt to pass explicit types for OffsetDateTime, OffsetTime, LocalDateTime, LocalDate, and LocalTime.
  • Add tests asserting explicit type arguments (and rejecting untyped calls) across affected libraries, and update samples to match.

^{Written for commit 55cb6e4. Summary will update on new commits.}

[cubic-dev-ai]

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