[3006.x] Correct bash-completion for Debian / Ubuntu

[dmurphy18]

What does this PR do?

Corrects bash-completion for Debian / Ubuntu. When the relenv architecture was created, the RedHat bash completion file salt.bash was used for Debian / Ubuntu and installed into the incorrect directory. This rectifies this regression and uses the correct salt-common.bash-completion file and installs into the correct directory, namely /usr/share/bash-completion/completions with the file salt-common, as previously in classic packaging and the Debian and Ubuntu forks of the Salt Project.

What issues does this PR fix or reference?

Fixes https://github.com/saltstack/salt/issues/66560

Previous Behavior

Bash completion did not work on Debian / Ubuntu and installed into the incorrect directory with the wrong completion file, that is, the one used for RedHat family.

New Behavior

Bash completion now works on Debian / Ubuntu and installs into the correct directory

Merge requirements satisfied?

[NOTICE] Bug fixes or features added to Salt require tests.

• [ ] Docs
• [X] Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• [ ] Tests written/updated

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Yes/No

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