RFR: 8344316: Add extra line in security/auth/callback/TextCallbackHandler/Password.java to make clear it is not a JTReg test

[Mikhail Yankelevich]

* Add extra line in security/auth/callback/TextCallbackHandler/Password.java to make clear it is not a JTReg test
* Test will now fail if run with JTReg

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Commit messages:
 - format small change
 - 8344316: Add comment to make clear it is not a JTReg test & test will fail if run with JTReg

Changes: https://git.openjdk.org/jdk/pull/22951/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22951&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8344316
  Stats: 10 lines in 1 file changed: 9 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22951.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22951/head:pull/22951

PR: https://git.openjdk.org/jdk/pull/22951