fix no context is allowed at jobs.<job_id>.steps.with.entrypoint`

Author: rhysd

rule_expression.go

@@ -290,7 +290,7 @@ func (rule *RuleExpression) VisitStep(n *Step) error {
 				rule.checkString(i.Value, "jobs.<job_id>.steps.with")
 			}
 		}
-		rule.checkString(e.Entrypoint, "")
+		rule.checkString(e.Entrypoint, "jobs.<job_id>.steps.with")
 		rule.checkString(e.Args, "jobs.<job_id>.steps.with")
 		spec = e.Uses
 	}

testdata/ok/issue-495_with_args.yaml

@@ -10,4 +10,5 @@ jobs:
     steps:
       - uses: docker://example.com:latest
         with:
+          entrypoint: --arg "${{ inputs.test }}"
           args: --arg "${{ inputs.test }}"