Make config required arg in ert_api_parser

[jaakson]

The ert api subparser was being passed to an add_parser_options function that added config as an optional argument when it should be required.

Issue
Resolves #13602

Approach

• Dropped config from add_parser_options

• Moved the optional config arg addition where it was needed

• Added required config to ert_api_parser the way it's done for other subparsers

• PR title captures the intent of the changes, and is fitting for release notes.

• Added appropriate release note label

• Commit history is consistent and clean, in line with the contribution guidelines.

• Make sure unit tests pass locally after every commit (git rebase -i main --exec 'just rapid-tests')

When applicable

• When there are user facing changes: Updated documentation
• New behavior or changes to existing untested code: Ensured that unit tests are added (See Ground Rules).
• Large PR: Prepare changes in small commits for more convenient review
• Bug fix: Add regression test for the bug
• Bug fix: Add backport label to latest release (format: 'backport release-branch-name')

[codecov-commenter]

Codecov Report

❌ Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.91%. Comparing base (e768c62) to head (82d59a3).
⚠️ Report is 20 commits behind head on main.

Files with missing lines	Patch %	Lines
src/ert/services/_storage_main.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13685      +/-   ##
==========================================
+ Coverage   89.38%   89.91%   +0.52%     
==========================================
  Files         469      468       -1     
  Lines       33391    33403      +12     
==========================================
+ Hits        29847    30034     +187     
+ Misses       3544     3369     -175     

Flag	Coverage Δ
cli-tests	35.79% <50.00%> (+0.03%)	⬆️
fuzz	43.38% <50.00%> (-0.05%)	⬇️
gui-tests	59.28% <50.00%> (-0.06%)	⬇️
performance-and-unit-tests	77.82% <50.00%> (-0.03%)	⬇️
test	45.90% <0.00%> (+0.92%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/ert/__main__.py	85.94% <100.00%> (+0.04%)	⬆️
src/ert/services/_storage_main.py	43.60% <0.00%> (-0.59%)	⬇️

... and 16 files with indirect coverage changes

[andreas-el]

You can consider adding a test in test_cli.py

Possibly pick up output using;

ert_process = Popen(<command>, stdout=PIPE, stderr=PIPE)
stdout, stderr = ert_process.communicate()

[codspeed-hq]

Merging this PR will not alter performance

✅ 36 untouched benchmarks

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_{Comparing jaakson:13602-ert-api-zero-arguments-bug (25206e7) with main (e7fc16b)}