RFR: 8367702: PrintJob.getGraphics() should return null after PrintJob.end

[Phil Race]

A few days ago it was noticed that there was a printing test (in closed) that didn't have a test tag and on closer examination that was unfortunate because it tested that PrintJob.getGraphics() returns null after PrintJob.end() and that was broken by a recent JDK 26 change

This fixes that and creates an updated open jtreg test so this should not happen again.
The above will restore the status quo but it was also noted that the PrintJob spec. doesn't describe this.
I prefer to handle the spec update separately and will do so as soon as this is resolved.

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Commit messages:
 - 8367702

Changes: https://git.openjdk.org/jdk/pull/27458/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27458&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367702
  Stats: 67 lines in 2 files changed: 66 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27458.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27458/head:pull/27458

PR: https://git.openjdk.org/jdk/pull/27458