Add minor version to config entries

[emontnemery]

Proposed change

Add minor_version to config entries to allow backwards compatible config entry version changes

If minor versions differ but major versions are same, and the integration does not implement async_migrate_entry, integration setup will be allowed to continue.

Rationale

We are very conservative with versioning config entry data because it breaks downgrading to an older version of Home Assistant Core. This means in most cases we don't version, and the integrations instead do a kind of soft upgrade where they may for example do dict.get on config entry data which was not in an initial version, transform the data during setup etc.

As an alternative to this pattern, this PR adds a minor version, similar to that offered by the storage helper.
A bump of the minor version should be done whenever the newly added, or otherwise changed, data does not break older versions.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• 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 #
• This PR is related to issue:
• Link to documentation 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
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• 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

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies - a link to the changelog, or at minimum a diff between library versions is added to the PR description.
• Untested files have been added to .coveragerc.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[emontnemery]

Tests are needed

[frenck]

Thanks, @emontnemery 👍

../Frenck