Add "www" to generated tag QR code

[spacegaier]

Breaking change

Proposed change

Fixes missing "www" in generated tag QR code.

Note: My writable NFC tags have not arrived yet, so I am not actually able to test that out in HA, but since this is a trivial PR, I guess that should be fine for this PR 😄.

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 QR code generation does not match expected tag URL format for companion apps #7576
• This PR is related to issue:
• 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

[dshokouhi]

We may want to tag this for a milestone hotfix since the mobile apps expect a certain format