RFR: 7903394: Update version to 7.1.1

Mon Dec 5 19:51:53 UTC 2022

This PR updates jtreg's version to 7.1.1 and contains the cherry-picked bugfix for:
- [7903390: Summary reporter getter not thread-safe](https://github.com/openjdk/jtreg/commit/c7df9b59d243a8526de9121a2d58a90ef98fe034)

It also updates the CHANGELOG.md accordingly.

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

Commit messages:
 - 7903390: Summary reporter getter not thread-safe
 - 7903394: Update version to 7.1.1
 - 7903386: Update changelog for jtreg 7.1

Changes: https://git.openjdk.org/jtreg/pull/141/files
 Webrev: https://webrevs.openjdk.org/?repo=jtreg&pr=141&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903394
  Stats: 13 lines in 3 files changed: 9 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jtreg/pull/141.diff
  Fetch: git fetch https://git.openjdk.org/jtreg pull/141/head:pull/141

PR: https://git.openjdk.org/jtreg/pull/141