RFR: 8370074: Remove unused code in AbstractDebuggeeTest.java

[Albert Mingkun Yang]

Trivial removing dead code.

Test: tier1

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Commit messages:
 - vmtestbase-trivial

Changes: https://git.openjdk.org/jdk/pull/27863/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27863&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8370074
  Stats: 10 lines in 1 file changed: 0 ins; 10 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27863.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27863/head:pull/27863

PR: https://git.openjdk.org/jdk/pull/27863