RFR: 8367424: Cleanup unused time_remaining_ms update in G1CollectionSet::select_optional_groups

[Guanqiang Han]

Please review this PR. This is a trivial change that simply removes unused code.

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Commit messages:
 - 8367424: Cleanup unused time_remaining_ms update in G1CollectionSet::select_optional_groups

Changes: https://git.openjdk.org/jdk/pull/27229/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27229&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367424
  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27229.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27229/head:pull/27229

PR: https://git.openjdk.org/jdk/pull/27229