ci: Remove accidental copy-paste

Author: jpmckinney

.github/workflows/lint.yml

@@ -1,7 +1,5 @@
 name: Lint
 on: [push, pull_request]
-env:
-  BASEDIR: https://raw.githubusercontent.com/open-contracting/standard-maintenance-scripts/main
 jobs:
   build:
     if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != github.repository