Fix holiday HA language not supported

[gjohansson-ST]

Proposed change

Package babel does not support all flavors of language so we default to English
Mainly an issue with English flavors such as en-GB

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 Holiday Integration - Unknown error occurred #106552
• 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.

[home-assistant]

Hey there @jrieger, mind taking a look at this pull request as it has been labeled with an integration (holiday) you are listed as a code owner for? Thanks!

Code owner commands

Code owners of holiday can trigger bot actions by commenting:

• @home-assistant close Closes the pull request.
• @home-assistant rename Awesome new title Renames the pull request.
• @home-assistant reopen Reopen the pull request.
• @home-assistant unassign holiday Removes the current integration label and assignees on the pull request, add the integration domain after the command.
• @home-assistant add-label needs-more-information Add a label (needs-more-information, problem in dependency, problem in custom component) to the pull request.
• @home-assistant remove-label needs-more-information Remove a label (needs-more-information, problem in dependency, problem in custom component) on the pull request.

[jrieger]

python-holidays uses BCP 47 language tags, so it is en_GB there instead of en-GB. Maybe you could just replace the hyphen with an underscore?

[gjohansson-ST]

Probably a good idea but I'll keep the exception around anyhow

[frenck]

@gjohansson-ST This one should not have been merged, as it is missing the required coverage on the configuration flow:

Can you add that as soon as possible?

[gjohansson-ST]

@gjohansson-ST This one should not have been merged, as it is missing the required coverage on the configuration flow:

Can you add that as soon as possible?

@frenck should be fixed by #106559 but I'll make sure coverage is fixed in a follow-up if needed.

[gjohansson-ST]

Coverage is 100% in dev

---------- coverage: platform linux, python 3.11.4-final-0 -----------
Name                                              Stmts   Miss  Cover   Missing
-------------------------------------------------------------------------------
homeassistant/components/holiday/__init__.py         10      0   100%
homeassistant/components/holiday/calendar.py         52      0   100%
homeassistant/components/holiday/config_flow.py      45      0   100%
homeassistant/components/holiday/const.py             3      0   100%
-------------------------------------------------------------------------------
TOTAL                                               110      0   100%

[frenck]

Thanks, @gjohansson-ST!
Awesome 👍