Fix/typos and variable name

[semnil]

Description

• Fix undefined variable build_args to package_args in Ubuntu packaging step of package-plugin action. The --debug flag was being appended to a non-existent variable instead of the package_args array that is passed to the packaging script.
• Fix typo "Reelase" to "Release" in buildspec_common.cmake status message.

Motivation and Context

Found these issues while working on adding InnoSetup installer support to a plugin project based on this template.

1. In the Ubuntu packaging step of package-plugin/action.yaml, --debug is appended to an undefined variable build_args instead of package_args. The macOS step in the same file correctly uses package_args.
2. A typo "Reelase" in buildspec_common.cmake status message.

How Has This Been Tested?

• Verified by reading the source: build_args is never declared in the run: block of the Ubuntu packaging step, nor is it accessible from other steps (each run: block executes in a separate shell process in GitHub Actions)
• Confirmed the macOS packaging step in the same file uses package_args+=(--debug) as the correct reference implementation
• Searched the entire repository for all occurrences of build_args to rule out any shared state or external definition
• Verified that no errors occur when running GitHub Actions workflows
  • https://github.com/semnil/MixTrack2Source/actions/runs/23697818237

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Code cleanup (non-breaking change which makes code smaller or more readable)

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.