Partially revert "Switch loader to use json helper (#73872)"

[frenck]

This reverts commit 164eba7.

Proposed change

Partially reverts #73872 to address the CI segfault issues we have been running into for the past 5 days.

I've been able to reproduce it locally by creating a fresh venv with a full install of dependencies and running a partial test, like so:

pytest  --timeout=10 --cov=homeassistant.components.open_meteo --cov-report term-missing --cov-report xml:cov.xml --durations=0 --durations-min=0.5 tests/components/open_meteo

[1]    210018 segmentation fault (core dumped)  pytest --timeout=10 --cov=homeassistant.components.open_meteo --cov-report   

Resulting backtrace from the core dump:

Reading symbols from /home/frenck/.pyenv/versions/3.9.9/envs/home-assistant-core/bin/python3.9...
[New LWP 210018]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `/home/frenck/.pyenv/versions/3.9.9/envs/home-assistant-core/bin/python3.9 /home'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x000055a2ec81e5d4 in _Py_Dealloc (op=0x55a2eed919c0) at Objects/object.c:2209
2209    Objects/object.c: No such file or directory.

I was able to git bisect it, resulting in:

Testing it in draft/testing PR #74046 showed it resolved the segfault in our CI too.

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)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

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