Fix typo and remove redundant `@since` tags. -------------
Commit messages: - JDK-8342653: Fix minor doc issues in AnnotatedElement Changes: https://git.openjdk.org/jdk/pull/21597/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21597&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8342653 Stats: 5 lines in 1 file changed: 0 ins; 4 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/21597.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21597/head:pull/21597 PR: https://git.openjdk.org/jdk/pull/21597
