RFR: 8344906: Simplify Java version parsing in the build file

[Nir Lisker]

Replaces the manual versions handling with [Version](https://docs.oracle.com/en/java/javase/23/docs/api/java.base/java/lang/Runtime.Version.html).

Changes:
* Removed the methods `parseJavaVersion(String)`, `parseJdkVersion(String)` and `compareJdkVersion(String, String)`, and replaced them with `Version.parse` and `Version.compareTo` methods.
* Removed the build properties of the Java version on which the Gradle build runs because they are only used for logging. Replaced with logging them directly. Note that Gradle logs by itself the info of the runtime it uses, so there's no need to logs these manually.
* Simplified the build JDK version by working directly with `Version` instead of a `String`. This allows to store less build properties. Also used try-with-resources to close the stream. Note that the whole build JDK manual invocation hack should be replaced with the Java Toolchain.
* Simplified the `verifyJava` task, which could also be replaced with built-in Gradle tools.

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Commit messages:
 - Fix whitespaces
 - Remove unused parsing method
 - Initial commit

Changes: https://git.openjdk.org/jfx/pull/1647/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1647&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8344906
  Stats: 97 lines in 1 file changed: 5 ins; 77 del; 15 mod
  Patch: https://git.openjdk.org/jfx/pull/1647.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1647/head:pull/1647

PR: https://git.openjdk.org/jfx/pull/1647