RFR: Run Windows CI using cmd

[Robin Westberg]

Hi all,

Please review this change that ensures that gradlew.bat is run using cmd when using GitHub actions on Windows.

Best regards,
Robin

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

Commits:
 - 41cd9d8e: Run Windows CI using cmd

Changes: https://git.openjdk.java.net/skara/pull/224/files
 Webrev: https://webrevs.openjdk.java.net/skara/224/webrev.00
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/skara/pull/224.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/224/head:pull/224

PR: https://git.openjdk.java.net/skara/pull/224