feat(tools): remove eslint-plugin-prettier for prettier (#42438)

* feat: remove eslint-plugin-prettier for prettier

This removes the annoying lint warnings when all that needs to change is
formatting

* fix: use .js lint-staged config to ignore properly

* fix: lint everything if a lot of files are changed

It's faster than making lots of individual linter calls

* chore: apply prettier

* fix: ignore code in curriculum-file-structure

tools/contributor/lib/pr-tasks/add-labels.js

@@ -11,7 +11,7 @@ const addLabels = (number, labels, log) => {
     .then(() => {
       console.log(`PR #${number} added ${JSON.stringify(labels)}\n`);
     })
-    .catch(err => {
+    .catch((err) => {
       console.log(
         `PR #${number} had an error when trying to labels: ${JSON.stringify(
           labels