Albrja/build utils/mic 7254/turn cov off, enable n auto (#158)

Albrja/build utils/mic 7254/turn cov off

Turn on n auto and turn off coverage for test step of CI
- *Category*: CI
- *JIRA issue*: https://jira.ihme.washington.edu/browse/MIC-7254

Changes and notes
-turns --cov off to save runtime
-enables n auto from pytest plugin

Author: albrja

libs/build-utils/CHANGELOG.rst

@@ -1,7 +1,12 @@
+**4.2.0 - 06/29/26**
+
+- Run pytest with ``-n auto`` by default to parallelize tests across available workers
+- Turn coverage off by default
+
 **4.1.0 - 06/29/26**
 
 - Run mypy in CI based on the presence of a ``py.typed`` marker under ``src/``
-- Centralize py.typed marker logic in a new ``mypy-if-typed`` Make target 
+- Centralize py.typed marker logic in a new ``mypy-if-typed`` Make target
 - Deprecate the ``run_mypy`` ``reusable_pipeline`` argument; it is still accepted but ignored
 
 **4.0.2 - 06/24/26**

libs/build-utils/pyproject.toml

@@ -17,7 +17,7 @@ dependencies = []
 cluster = []
 docs = []
 interactive = []
-test = ["vivarium-dependencies[pytest]"]
+test = ["vivarium-dependencies[pytest]", "pytest-xdist"]
 lint = ["vivarium-dependencies[lint]"]
 dev = ["vivarium-build-utils[docs,interactive,test,lint]"]
 ci_github = ["vivarium-build-utils[test,docs,lint]"]

libs/build-utils/resources/makefiles/test.mk

@@ -1,11 +1,11 @@
 define test
 	export COVERAGE_FILE=./output/.coverage.$(1) && \
-	pytest -vvv $(if $(RUNSLOW),--runslow,) $(if $(RUNWEEKLY),--runweekly,) --cov --cov-report term --cov-report html:./output/htmlcov_$(1) tests/$(1)
+	pytest -vvv -n auto $(if $(RUNSLOW),--runslow,) $(if $(RUNWEEKLY),--runweekly,) $(if $(COV),--cov --cov-report term --cov-report html:./output/htmlcov_$(1),) tests/$(1)
 endef
 
 test-all: # Run all tests
 	export COVERAGE_FILE=./output/.coverage && \
-	pytest -vvv $(if $(RUNSLOW),--runslow,) $(if $(RUNWEEKLY),--runweekly,) --cov --cov-report term --cov-report html:./output/htmlcov_tests tests/
+	pytest -vvv -n auto $(if $(RUNSLOW),--runslow,) $(if $(RUNWEEKLY),--runweekly,) $(if $(COV),--cov --cov-report term --cov-report html:./output/htmlcov_tests,) tests/
 
 test-e2e: # Run end-to-end tests
 	$(call test,e2e)