Tweak make env to get docs to build on actions

Makefile

@@ -13,6 +13,7 @@ TEST_ARGS := -v --cov=$(PACKAGE_NAME) --cov-report=term --cov-report=xml --junit
 env:
 	mamba create     --name $(PACKAGE_NAME)
 	mamba env update --name $(PACKAGE_NAME) --file devtools/conda-envs/test.yaml
+	conda activate $(PACKAGE_NAME)
 	$(CONDA_ENV_RUN) pip install --no-deps -e .
 	$(CONDA_ENV_RUN) pre-commit install || true