RFR: 8343173: Remove ZGC-specific non-JVMCI test groups

[Leonid Mesnik]

The JVMCI should be supported by all GCs and specific
hotspot_compiler_all_gcs
group is not needed anymore.

There are few failures of JVMCI tests with ZGC happened, the bug 
https://bugs.openjdk.org/browse/JDK-8343233
is filed and corresponding tests are problemlisted.

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Commit messages:
 - 8343173: Remove ZGC-specific non-JVMCI test groups

Changes: https://git.openjdk.org/jdk/pull/21774/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21774&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343173
  Stats: 20 lines in 3 files changed: 16 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21774.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21774/head:pull/21774

PR: https://git.openjdk.org/jdk/pull/21774