RFR: 8219357: G1: G1GCPhaseTimes::debug_phase uses unnecessary ResourceMark

[Thomas Schatzl]

Hi all,

  please review this removal of an unnecessary `ResourceMark`.

Testing: local compilation, gha

Thanks,
  Thomas

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Commit messages:
 - initial version

Changes: https://git.openjdk.org/jdk/pull/14512/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14512&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8219357
  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/14512.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14512/head:pull/14512

PR: https://git.openjdk.org/jdk/pull/14512