ci: verify gradle wrapper

[lionel-nj]

relates to #734

Summary:

This PR provides support to verify the gradle wrapper by adding a job to the test_pack_docworkflow.

This adds additional security/integrity to ensure that any changes to the wrapper match an official Gradle release.
(from #963 (review))

Said job is required to execute test, packaging and documentation jobs.

Expected behavior:

Workflows fail if the SHA-256 checksum does not match an official release from Gradle.

Please make sure these boxes are checked before submitting your pull request - thanks!

• [ ] Run the unit tests with gradle test to make sure you didn't break anything
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
• [ ] Include screenshot(s) showing how this pull request works and fixes the issue(s)

[barbeau]

@lionel-nj Could you add this to all the workflows? It should be the very first step in any workflow that executes Gradle so that if the validation of the wrapper fails no additional steps in the workflow should be executed.

[lionel-nj]

@lionel-nj Could you add this to all the workflows? It should be the very first step in any workflow that executes Gradle so that if the validation of the wrapper fails no additional steps in the workflow should be executed.

Done in 179dae0.

[barbeau]

LGTM, thanks!