Fix demo

[balloob]

Description:

• Discovery now requires hass_config to be passed in
• async_setup_component now requires config to be passed in
• Fixes the demo tests.
• Fixes an issue where loading the scene integration would result in the integration component being set up twice.
• Demo compnent will only load when explicitly mentioned in the config, won't set itself up as part of setting up a demo platform.
• Remove groups from demo
• Loading the demo integration will no longer interfere with other integrations that are being set up, as we no longer call async_setup_component during our own async_setup, but use platform discovery instead.

Related issue (if applicable): fixes #23003

Pull request in home-assistant.io with documentation (if applicable): home-assistant/home-assistant.io#<home-assistant.io PR number goes here>

Example entry for configuration.yaml (if applicable):

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.

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

• Documentation added/updated in home-assistant.io

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

• The manifest file has all fields filled out correctly (example).
• New dependencies have been added to requirements in the manifest (example).
• New dependencies are only imported inside functions that use them (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[github-actions]

Hey there @home-assistant/core, mind taking a look at this pull request as its been labeled with a integration (demo) you are listed as a codeowner for? Thanks!

[codecov]

Codecov Report

Merging #23087 into dev will decrease coverage by 32.17%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##              dev   #23087       +/-   ##
===========================================
- Coverage   93.95%   61.77%   -32.18%     
===========================================
  Files         452      452               
  Lines       36798    36789        -9     
===========================================
- Hits        34572    22725    -11847     
- Misses       2226    14064    +11838

Impacted Files	Coverage Δ
homeassistant/loader.py	83.01% <ø> (-10.85%)	⬇️
homeassistant/helpers/discovery.py	89.47% <ø> (-10.53%)	⬇️
homeassistant/helpers/entity_component.py	93.98% <ø> (-2.26%)	⬇️
homeassistant/bootstrap.py	59.25% <0%> (+0.47%)	⬆️
homeassistant/components/automation/template.py	0% <0%> (-100%)	⬇️
homeassistant/components/litejet/switch.py	0% <0%> (-100%)	⬇️
homeassistant/components/automation/state.py	0% <0%> (-100%)	⬇️
homeassistant/components/worldclock/sensor.py	0% <0%> (-100%)	⬇️
...omeassistant/components/logi_circle/config_flow.py	0% <0%> (-100%)	⬇️
homeassistant/components/smhi/weather.py	0% <0%> (-100%)	⬇️
... and 214 more

---

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[codecov]

Codecov Report

Merging #23087 into dev will increase coverage by 0.14%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##              dev   #23087      +/-   ##
==========================================
+ Coverage   93.95%   94.09%   +0.14%     
==========================================
  Files         452      452              
  Lines       36798    36789       -9     
==========================================
+ Hits        34572    34617      +45     
+ Misses       2226     2172      -54

Impacted Files	Coverage Δ
homeassistant/loader.py	93.86% <ø> (ø)	⬆️
homeassistant/helpers/discovery.py	100% <ø> (ø)	⬆️
homeassistant/helpers/entity_component.py	96.24% <ø> (ø)	⬆️
homeassistant/bootstrap.py	59.25% <0%> (+0.47%)	⬆️
setup.py	86.5% <0%> (-0.33%)	⬇️
...assistant/components/manual/alarm_control_panel.py	98.74% <0%> (+0.62%)	⬆️
homeassistant/components/demo/device_tracker.py	100% <0%> (+78.57%)	⬆️
homeassistant/components/demo/sensor.py	100% <0%> (+100%)	⬆️
homeassistant/components/demo/binary_sensor.py	100% <0%> (+100%)	⬆️

---

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Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 3368e30...074da0b. Read the comment docs.