Fix free-disk-space version in example

[JohannesDeml]

Old version 1.2.0 throws the error E: Unable to locate package google-cloud-sdk, version 1.3.0 fixes this. Tested here: https://github.com/JohannesDeml/Unity-GameJam-Template/commit/60af3abdad4ede3bd38a3055535c8570b15e81a7

Changes

• Update free-disk-space from version 1.2 to 1.3 in full example to make it work again

Checklist

• [x] Read the contribution guide and accept the code of conduct
• [x] Readme (updated or not needed)
• [x] Tests (added, updated or not needed)

[github-actions[bot]]

[GabLeRoux]

Awesome, thanks!