Fix schema and add invalid examples

Signed-off-by: Charles d'Avernas <charles.davernas@neuroglia.io>

Author: cdavernas

.ci/validation/test/fixtures/invalid/listen-any-empty-no-until.yaml

@@ -0,0 +1,10 @@
+document:
+  dsl: '1.0.0-alpha1'
+  namespace: test
+  name: listen-to-any
+  version: '0.1.0'
+do:
+  - callDoctor:
+      listen:
+        to:
+          any: []

.ci/validation/test/fixtures/invalid/listen-any-until-any-until.yaml

@@ -0,0 +1,14 @@
+document:
+  dsl: '1.0.0-alpha1'
+  namespace: test
+  name: listen-to-any
+  version: '0.1.0'
+do:
+do:
+  - callDoctor:
+      listen:
+        to:
+          any: []
+          until:
+            any: []
+            until: ${ ($context.events | length) == 3 }

schema/workflow.yaml

@@ -1319,9 +1319,12 @@ $defs:
                   - type: string
                     title: AnyEventUntilCondition
                     description: A runtime expression condition evaluated after consuming an event and which determines whether or not to continue listening.
-                  - $ref: '#/$defs/eventConsumptionStrategy'
-                    title: AnyEventUntilConsumed
-                    description: The strategy that defines the event(s) to consume to stop listening.
+                  - allOf:
+                      - $ref: '#/$defs/eventConsumptionStrategy'
+                        title: AnyEventUntilConsumed
+                        description: The strategy that defines the event(s) to consume to stop listening.
+                      - properties:
+                          until: false
             required: [ any ]
           - properties:
               any:
@@ -1336,9 +1339,12 @@ $defs:
                   - type: string
                     title: AnyEventUntilCondition
                     description: A runtime expression condition evaluated after consuming an event and which determines whether or not to continue listening.
-                  - $ref: '#/$defs/eventConsumptionStrategy'
-                    title: AnyEventUntilConsumed
-                    description: The strategy that defines the event(s) to consume to stop listening.
+                  - allOf:
+                      - $ref: '#/$defs/eventConsumptionStrategy'
+                        title: AnyEventUntilConsumed
+                        description: The strategy that defines the event(s) to consume to stop listening.
+                      - properties:
+                          until: false
             required: [ any, until ]
       - title: OneEventConsumptionStrategy
         properties: