RFR: 8374434: Several JShell tests report JUnit discovery warnings [v2]

[Jan Lahoda]

> JShell tests where converted to use JUnit instead of TestNG by this commit:
> https://github.com/openjdk/jdk/commit/b0ca9bf61e0390a3b022a0915eacabb0cfd92e93
> 
> As part of the conversion, the `@Test` annotation had to be copied from classes to test methods, as JUnit requires every test method to be annotated. Sadly the tool doing the conversion moved the annotation to some non-test methods as well. This PR fixes that. The tool has been fixed as well.

Jan Lahoda has updated the pull request incrementally with one additional commit since the last revision:

  Updating copyright years.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/29034/files
  - new: https://git.openjdk.org/jdk/pull/29034/files/ffd0df4f..052e0583

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29034&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29034&range=00-01

  Stats: 3 lines in 3 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/29034.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29034/head:pull/29034

PR: https://git.openjdk.org/jdk/pull/29034