pickmydegree stops tracking its own generated coverage reports

pickmydegree had been committing the HTML output of its test-coverage run, and CodeQL flagged the Istanbul report’s sorter.js assets as js/xss-through-dom inside that generated output (11e72fc). Those files are test artifacts rather than application code, so coverage/ is now ignored and the committed reports left the tree — roughly 22,800 lines of generated HTML and CSS removed and three added, merged as PR #2. The app source is untouched; only the repository stops carrying a copy of its own coverage run.