[jdk19] RFR: 8290625: Test jdk/javadoc/tool/CheckManPageOptions.java after manpage update

[David Holmes]

[JDK-8278274](https://bugs.openjdk.org/browse/JDK-8278274) just brought the nroff manpage into sync with its markdown source. But this test examines the nroff manpage and needs to be updated as the `--date` option is no longer missing.

Thanks.

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Commit messages:
 - 8290625: Test jdk/javadoc/tool/CheckManPageOptions.java after manpage update

Changes: https://git.openjdk.org/jdk19/pull/149/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=149&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8290625
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk19/pull/149.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/149/head:pull/149

PR: https://git.openjdk.org/jdk19/pull/149