RFR: 8305084: Remove finalize() from test/hotspot/jtreg/serviceability/dcmd/gc/ that are used in serviceability/dcmd/gc/

[Afshin Zafari]

The `removal` warnings are suppressed out.
Test:
`FinalizerInfoTest` and `RunFinalizationTest` are executed locally.

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Commit messages:
 - 8305084: Remove finalize() from test/hotspot/jtreg/serviceability/dcmd/gc/ that are used in serviceability/dcmd/gc/

Changes: https://git.openjdk.org/jdk/pull/13423/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13423&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8305084
  Stats: 4 lines in 2 files changed: 1 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/13423.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13423/head:pull/13423

PR: https://git.openjdk.org/jdk/pull/13423