[jdk26u] RFR: 8376684: Compile OpenJDK in headless mode without required X11 libraries

[Thomas Devoogdt]

As requested in https://github.com/openjdk/jdk25u-dev/pull/242#issuecomment-3883209948, this is a try to get it back-ported to some of the LTS branches. (25, 21 and 17)

Upstream work: https://github.com/openjdk/jdk/commit/1069ccebcc32e02055985e2babfa2986a2e295ca

-------------

Commit messages:
 - Backport 1069ccebcc32e02055985e2babfa2986a2e295ca

Changes: https://git.openjdk.org/jdk26u/pull/53/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk26u&pr=53&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8376684
  Stats: 30 lines in 5 files changed: 14 ins; 5 del; 11 mod
  Patch: https://git.openjdk.org/jdk26u/pull/53.diff
  Fetch: git fetch https://git.openjdk.org/jdk26u.git pull/53/head:pull/53

PR: https://git.openjdk.org/jdk26u/pull/53