(PC-34429)[API] ci: use pytest-split to parallelize tests in GHA #11164

Job	Run time
Init job	39s
Tests API documentation	0s
Tests pro	0s
[pcapi] build docker image. / Build Docker image	2m 18s
MyPy cop / MyPy cop test	38s
[pcapi-console] build docker image. / Build Docker image	3m 37s
[pcapi-tests] build docker image. / Build Docker image	3m 48s
Merge Allure Reports and Push to Allure Repository	0s
Dependabot	0s
[PRO] Deploy PR version for validation pr preview backend	0s
[PRO] Deploy PR version for validation with testing backend	0s
Tests pro E2E / E2E tests and notifications	11m 53s
Update api client template / Update API Client template	2m 14s
Tests api / Quality checks	2m 47s
Tests api / Pylint	3m 57s
Tests api / Test database schema	2m 51s
Tests api / Pytest (without BO) : 1/4	5m 42s
Tests api / Pytest (without BO) : 2/4	5m 13s
Tests api / Pytest (without BO) : 3/4	5m 36s
Tests api / Pytest (without BO) : 4/4	5m 12s
Tests api / Pytest (only BO) : 1/4	4m 56s
Tests api / Pytest (only BO) : 2/4	4m 37s
Tests api / Pytest (only BO) : 3/4	6m 15s
Tests api / Pytest (only BO) : 4/4	4m 33s
Push pcapi docker image to registry	0s
Push pcapi-console docker image to registry	0s
	1h 16m 46s

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