make event in pipeline schema also a constraint_list (#3082)

pipeline/frontend/yaml/linter/schema/.woodpecker/test-pipeline-when.yml

@@ -10,6 +10,9 @@ when:
     cron:
       include:
         - hello
+  - event:
+      exclude: pull_request_closed
+    evaluate: 'CI_COMMIT_AUTHOR == "woodpecker-ci"'
 
 steps:
   echo:

pipeline/frontend/yaml/linter/schema/.woodpecker/test-when.yml

@@ -27,6 +27,14 @@ steps:
     when:
       event: [push, pull_request, tag, deployment]
 
+  when-event-exclude-pull_request_closed:
+    image: alpine
+    commands:
+      - echo "test"
+    when:
+      event:
+        exclude: pull_request_closed
+
   when-ref:
     image: alpine
     commands:

pipeline/frontend/yaml/linter/schema/schema.json

@@ -394,18 +394,7 @@
         },
         "event": {
           "description": "Read more: https://woodpecker-ci.org/docs/usage/pipeline-syntax#event",
-          "oneOf": [
-            {
-              "type": "array",
-              "minLength": 1,
-              "items": {
-                "$ref": "#/definitions/event_enum"
-              }
-            },
-            {
-              "$ref": "#/definitions/event_enum"
-            }
-          ]
+          "$ref": "#/definitions/event_constraint_list"
         },
         "ref": {
           "description": "Read more: https://woodpecker-ci.org/docs/usage/pipeline-syntax#ref",
@@ -495,6 +484,54 @@
     "event_enum": {
       "enum": ["push", "pull_request", "pull_request_closed", "tag", "deployment", "cron", "manual"]
     },
+    "event_constraint_list": {
+      "oneOf": [
+        {
+          "$ref": "#/definitions/event_enum"
+        },
+        {
+          "type": "array",
+          "minLength": 1,
+          "items": {
+            "$ref": "#/definitions/event_enum"
+          }
+        },
+        {
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "include": {
+              "oneOf": [
+                {
+                  "$ref": "#/definitions/event_enum"
+                },
+                {
+                  "type": "array",
+                  "minLength": 1,
+                  "items": {
+                    "$ref": "#/definitions/event_enum"
+                  }
+                }
+              ]
+            },
+            "exclude": {
+              "oneOf": [
+                {
+                  "$ref": "#/definitions/event_enum"
+                },
+                {
+                  "type": "array",
+                  "minLength": 1,
+                  "items": {
+                    "$ref": "#/definitions/event_enum"
+                  }
+                }
+              ]
+            }
+          }
+        }
+      ]
+    },
     "constraint_list": {
       "oneOf": [
         {