completion/system: load earlier than others

[gaelicWizard]

Description

Set BASH_IT_LOAD_PRIORITY to 325 so that the distro-provided bash-completions package is loaded before any other completions packaged here.

Motivation and Context

Several of the completions bundled in Bash It test whether another completion is already installed, however system sorts lexicographically fairly late in the alphabet so it is unlikely that our tests are succeeding. I chose 325 so that it's still possible to deliberately place something before this component, if needed somehow.

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the code style of this project.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• I have added tests to cover my changes, and all the new and existing tests pass.

[NoahGorny]

Hi @gaelicWizard, lets maybe add system.completion.bash into clean_files.txt if we are already touching it?

[gaelicWizard]

@NoahGorny, I'm simply not able to keep track of so many unmerged branches. I'm doing my best to split these things out so they can be merged piecemeal.