Use npx to ensure we're using the intended TS rather than an ambient one

Author: jessealama

.github/workflows/push.yaml

@@ -22,7 +22,7 @@ jobs:
             - name: lint
               run: npm run lint
             - name: compile typescript
-              run: tsc
+              run: npx tsc
             - name: test
               run: npm run test
             - name: generate coverage