fix: runs-on is also mandatory for reusable workflows and may be needing container (#194)

If not the schema validation will fail because it will be try to validate as if not calling a reusable workflow.

```
=== RUN   TestWorkflowCallRunsOn
    schema_test.go:119:
        	Error Trace:	/home/earl-warren/software/act/pkg/schema/schema_test.go:119
        	Error:      	Received unexpected error:
        	            	Line: 10 Column 5: Failed to match job-factory: Line: 12 Column 5: Unknown Property uses
        	            	Line: 13 Column 5: Unknown Property with
        	            	Line: 15 Column 5: Unknown Property secrets
        	            	Line: 10 Column 5: Failed to match workflow-job: Line: 11 Column 5: Unknown Property runs-on
        	Test:       	TestWorkflowCallRunsOn
```

Reviewed-on: https://code.forgejo.org/forgejo/act/pulls/194
Reviewed-by: Michael Kriese <michael.kriese@gmx.de>
Co-authored-by: Earl Warren <contact@earl-warren.org>
Co-committed-by: Earl Warren <contact@earl-warren.org>

act/schema/schema_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"gopkg.in/yaml.v3"
 )
 
@@ -90,3 +91,32 @@ jobs:
 	}).UnmarshalYAML(&node)
 	assert.NoError(t, err)
 }
+
+func TestWorkflowCallRunsOn(t *testing.T) {
+	var node yaml.Node
+	err := yaml.Unmarshal([]byte(`
+name: Build Silo Frontend DEV
+on:
+  push:
+    branches:
+      - dev
+      - dev-*
+jobs:
+  build_frontend_dev:
+    name: Build Silo Frontend DEV
+    runs-on: ubuntu-latest
+    container:
+      image: code.forgejo.org/oci/node:22-bookworm
+    uses: ./.github/workflows/build.yaml
+    with:
+      STAGE: dev
+    secrets:
+      PACKAGE_WRITER_TOKEN: ${{ secrets.PACKAGE_WRITER_TOKEN }}
+`), &node)
+	require.NoError(t, err)
+	n := &Node{
+		Definition: "workflow-root",
+		Schema:     GetWorkflowSchema(),
+	}
+	require.NoError(t, n.UnmarshalYAML(&node))
+}

act/schema/workflow_schema.json

@@ -1472,6 +1472,11 @@
             "type": "non-empty-string",
             "required": true
           },
+          "runs-on": {
+            "type": "runs-on",
+            "required": true
+          },
+          "container": "container",
           "with": "workflow-job-with",
           "secrets": "workflow-job-secrets",
           "needs": "needs",