[Kotlin] Upgrade jackson version used in the Kotlin client

[zapodot]

To fix #8688

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[4brunu]

I'm not a user of Jackson, so it's hard for me to review this PR.
I have one question, does Jackson require kotlin reflect dependency?

[zapodot]

I'm not a user of Jackson, so it's hard for me to review this PR.
I have one question, does Jackson require kotlin reflect dependency?

Yes, according to the pom of jackson-module-kotlin it does depend on kotlin-reflect: https://github.com/FasterXML/jackson-module-kotlin/blob/master/pom.xml

[wing328]

LGTM but I've not tested it locally

[wing328]

@zapodot thanks for the PR, which has been included in the v5.1.0 release: https://twitter.com/oas_generator/status/1373636654024380423