chore(ci): upgraded linter to 1.53.3 (#3079)

* chore(ci): upgraded linter to 1.53.3

This flagged a bunch of unused parameters, so the PR is larger than
usual, but 99% mechanical.

* separate lint CI task

* run Lint in separate CI

internal/diff/diff.go

@@ -292,7 +292,7 @@ func downloadFile(ctx context.Context, f fs.File, fname string) error {
 		return errors.Wrap(err, "error creating file to edit")
 	}
 
-	defer dst.Close() //nolint:errcheck,gosec
+	defer dst.Close() //nolint:errcheck
 
 	return errors.Wrap(iocopy.JustCopy(dst, src), "error downloading file")
 }