RFR: 8329012: IGV: Update required JDK version in README.md

[Roberto Castañeda Lozano]

On Tue, 26 Mar 2024 02:48:35 GMT, Jie Fu <jiefu at openjdk.org> wrote:

> While building IGV, I found the jdk version described in the README.md is incorrect.
> 
> According to the pom.xml: https://github.com/openjdk/jdk/blob/master/src/utils/IdealGraphVisualizer/pom.xml#L82 
> It should be updated to "between 17 and 21".
> 
> Thanks.
> Best regards,
> Jie

Thanks for fixing this! You can consider this changeset trivial.

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Marked as reviewed by rcastanedalo (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18481#pullrequestreview-1959328600