Always execute lint check (#47)

Ensure that the lint check is always performed on push and pull-requests
on main. This fixes the corresponding mandatory check being stuck.

.github/workflows/lint.yml

@@ -4,19 +4,9 @@ on:
   push:
     branches:
       - 'main'
-    paths:
-      - 'pfdl_scheduler/**'
-      - 'tests/**'
-      - 'ci_lint_runner.py'
-      - '.github/workflows/**'
   pull_request:
     branches:
       - 'main'
-    paths:
-      - 'pfdl_scheduler/**'
-      - 'tests/**'
-      - 'ci_lint_runner.py'
-      - '.github/workflows/**'
 
 permissions:
   contents: read