Update XMP Toolkit submodule to August 2021 Release - try again for Github Actions

[egfx-notifications]

Changes in This Pull Request

Simply updating the XMP Toolkit submodule to the current (August 2021) Release.
No changes to the Rust code itself.
For changes in the XMP Toolkit see https://github.com/adobe/XMP-Toolkit-SDK/releases/tag/v2021.08

Checklist

• This PR represents a single feature, fix, or change.
• All applicable changes have been documented.
• Any TO DO items (or similar) have been entered as GitHub issues and the link to that issue has been included in a comment.

[egfx-notifications]

@scouten-adobe Guess I found the problem. Your workflows only trigger on push. For them to run on PRs from forks as well, you need to change your workflows from

on: [push]

to

on:  
  push:
  pull_request:
    branches:
      - main

[scouten-adobe]

Closed in favor of #26, which resolves some merge conflicts. Thank you!

Release coming momentarily.

[scouten-adobe]

Released as version 0.2.0 on https://crates.io/crates/xmp_toolkit.