[jdk22] RFR: 8323547: tools/jlink/plugins/SystemModuleDescriptors/ModuleMainClassTest.java fails to compile

[Mandy Chung]

`jdk.test.lib.process.ProcessTools::executeTools` was modified to throw Exception by JDK-8322920 that has only been in the main line.   It's a mistake to backport JDK-8322809 without catching this.   Trivial fix - update the signature to throw Throwable instead.

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Commit messages:
 - 8323547: tools/jlink/plugins/SystemModuleDescriptors/ModuleMainClassTest.java fails to compile

Changes: https://git.openjdk.org/jdk22/pull/58/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk22&pr=58&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8323547
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk22/pull/58.diff
  Fetch: git fetch https://git.openjdk.org/jdk22.git pull/58/head:pull/58

PR: https://git.openjdk.org/jdk22/pull/58