RFR: 8326892: Remove unused PSAdaptiveSizePolicyResizeVirtualSpaceAlot develop flag

[Zhengyu Gu]

Trivial cleanup, remove unused develop flag.

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Commit messages:
 - 8326892: Remove unused PSAdaptiveSizePolicyResizeVirtualSpaceAlot develop flag

Changes: https://git.openjdk.org/jdk/pull/18036/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18036&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8326892
  Stats: 4 lines in 1 file changed: 0 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/18036.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18036/head:pull/18036

PR: https://git.openjdk.org/jdk/pull/18036