[jdk17u-dev] RFR: 8294941: GHA: Cut down cross-compilation sysroots

[Aleksey Shipilev]

Clean backport to improve GHA footprint overheads.

Additional testing:
 - [ ] GHA

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Commit messages:
 - Backport a1747ef81a10e84177f474565193204ceaa0ede8

Changes: https://git.openjdk.org/jdk17u-dev/pull/1661/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1661&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8294941
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1661.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1661/head:pull/1661

PR: https://git.openjdk.org/jdk17u-dev/pull/1661