Updating parent pom and bom

[aneveux]

Hello folks 👋

I'm currently following the Improve a Plugin documentation for
Jenkins plugins modernization, and noticed we could update the parent pom for this plugin.

So here's a PR doing that. I checked that everything is running fine with mvn verify and removed unnecessary
upperbounds dependencyManagement.

Thanks for your review!

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[aneveux]

Hello @jglick, @Vlatombe 👋

Can you please have a look at that PR? ❤️

[jglick]

Looks fine, but I do not have write access.