RFR: 8410: Update version for 9.1.1 release

[Virag Purnam]

Updated version from 9.1.0 to 9.1.1 for JMC micro release.

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

Commit messages:
 - 8410: hardcoded version in pom
 - 8410: Update version for 9.1.1 release

Changes: https://git.openjdk.org/jmc/pull/659/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=659&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8410
  Stats: 217 lines in 152 files changed: 0 ins; 0 del; 217 mod
  Patch: https://git.openjdk.org/jmc/pull/659.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/659/head:pull/659

PR: https://git.openjdk.org/jmc/pull/659