libobs: Add Flatpak commit logging

[tytan652]

Description

This can allow to determinate the origin of a Flatpak build

Motivation and Context

This PR is meant to allow the loganalyzer (if provided with ostree commit hashes) to see if the build is one that we pushed to Flathub or Flathub Beta.

How Has This Been Tested?

Not tested, I need the CI artifact to do so. Artifacts logs the commit hash as expected

Types of changes

• Tweak (non-breaking change to improve existing functionality)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[RytoEX]

Commit message:

• determinate -> determine