supervisor/backup: Ensure compressed flag is respected by homeassistant

[3v1n0]

Proposed change

As per commit 80e67b3 we're supporting a compressed flag on backups to
define whether a tar archive should be fully compressed or not, but
while we respect this for all the addons and folders we don't do it for
the actual homeassistant archive, that is always compressed despite the
passed flag.

Fix this by applying the same logic to the homeassistant archive too.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (which adds functionality to the supervisor)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes Uncompressed backups contains compressed home asstant archive #3838
• This PR is related to issue:
• Link to documentation pull request:
• Link to cli pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast supervisor tests)
• Tests have been added to verify that the new code works.

If API endpoints of add-on configuration are added/changed:

• Documentation added/updated for developers.home-assistant.io