RFR: 8308335 JFR: Remove @Experimental from Virtual Threads events [v2]

[Erik Gahlin]

> Virtual threads is no longer in preview and experimental annotation should be removed.
> 
> Testing: test/jdk/jdk/jfr
> 
> Thanks
> erik

Erik Gahlin has updated the pull request incrementally with one additional commit since the last revision:

  Remove unused imports

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/14133/files
  - new: https://git.openjdk.org/jdk/pull/14133/files/4c035bd9..8965a5ca

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14133&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14133&range=00-01

  Stats: 4 lines in 4 files changed: 0 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/14133.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14133/head:pull/14133

PR: https://git.openjdk.org/jdk/pull/14133