Makefile+docs: Migrate YAML linting to own makefile target.

This commit moves the YAML linting logic in the Makefile to be under the
new `check-yaml-tests` target, so that the `make check` target does not
mix Go and YAML errors together.

Signed-off-by: Philip Conrad <philipaconrad@gmail.com>

Makefile

@@ -148,11 +148,6 @@ ifeq ($(DOCKER_RUNNING), 1)
 else
 	@echo "Docker not installed or running. Skipping golangci run."
 endif
-ifeq ($(DOCKER_RUNNING), 1)
-	docker run --rm -v $(shell pwd):/data:ro,Z -w /data pipelinecomponents/yamllint:${YAML_LINT_VERSION} yamllint test/cases/testdata
-else
-	@echo "Docker not installed or running. Skipping yamllint run."
-endif
 
 .PHONY: fmt
 fmt:
@@ -480,6 +475,14 @@ check-go-module:
 	  $(RELEASE_BUILD_IMAGE) \
 	  /bin/bash -c "git config --system --add safe.directory /src && go mod vendor -v"
 
+.PHONY: check-yaml-tests
+check-yaml-tests:
+ifeq ($(DOCKER_RUNNING), 1)
+	docker run --rm -v $(shell pwd):/data:ro,Z -w /data pipelinecomponents/yamllint:${YAML_LINT_VERSION} yamllint test/cases/testdata
+else
+	@echo "Docker not installed or running. Skipping yamllint run."
+endif
+
 ######################################################
 #
 # Release targets

docs/content/contrib-development.md

@@ -74,6 +74,8 @@ git rebase upstream/main
 > style.
 > For YAML files, you may need to run the `yamllint` tool on the
 > `test/cases/testdata` folder to make sure any new tests are well-formatted.
+> If you have Docker available, you can run `make check-yaml-tests` to
+> run `yamllint` on the tests without installing any Python dependencies.
 
 
 ### Submission