Only create sortable when not disabled

[silamon]

Proposed change

Sortable is only created when disabled is explicitly false unless you come back to the page and it connects again. This adds the disabled check in the connectedCallback as well.

To reproduce in demo:

1. Open the section page (https://demo.home-assistant.io/#/lovelace)
2. Switch to Energy
3. Switch back to section page

Type of change

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

Example configuration

Additional information

• This PR fixes or closes issue: fixes Cards in sections are drag-droppable when not in Edit Dashboard mode #20522
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

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

[piitaya]

Thank you @silamon !