chore: remove lint alias from Makefile

`quality` is the established standard across the Open edX ecosystem.
The `lint` alias was unnecessary and potentially confusing.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: farhan

Makefile

@@ -1,4 +1,4 @@
-.PHONY: help clean upgrade requirements test-python test quality quality-python lint
+.PHONY: help clean upgrade requirements test-python test quality quality-python
 
 .DEFAULT_GOAL := help
 
@@ -28,8 +28,6 @@ quality-python: ## Run python linters
 
 quality: quality-python ## Run linters
 
-lint: quality ## Run linting checks (alias for quality)
-
 test-python: clean ## run tests using pytest and generate coverage report
 	uv run tox -e py312