RFR: 8350437: [GHA] Update gradle wrapper-validation action to v3

[Kevin Rushforth]

Update the GitHub gradle wrapper-validation action to v3. In addition to being a good practice in general, we've had a few intermittent failures in the existing validation task, and updating to the latest might help with this.

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Commit messages:
 - [GHA] Update gradle wrapper-validation action to v3

Changes: https://git.openjdk.org/jfx/pull/1718/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1718&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8350437
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1718.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1718/head:pull/1718

PR: https://git.openjdk.org/jfx/pull/1718