Fix 'occured' -> 'occurred' typos across Python, Go, and Java SDKs

sdks/go/pkg/beam/runners/prism/internal/engine/teststream.go

@@ -230,7 +230,7 @@ func (ev tsWatermarkEvent) Execute(em *ElementManager) {
 		ss.updateUpstreamWatermark(ss.inputID, t.watermark)
 		em.changedStages.insert(sID)
 	}
-	// Clear the default hold after the inserts have occured.
+	// Clear the default hold after the inserts have occurred.
 	em.testStreamHandler.UpdateHold(em, t.watermark)
 }
 

sdks/java/testing/nexmark/src/main/java/org/apache/beam/sdk/nexmark/sources/generator/Generator.java

@@ -56,7 +56,7 @@ public static class NextEvent implements Comparable<NextEvent> {
     /** When, in wallclock time, should this event be emitted? */
     public final long wallclockTimestamp;
 
-    /** When, in event time, should this event be considered to have occured? */
+    /** When, in event time, should this event be considered to have occurred? */
     public final long eventTimestamp;
 
     /** The event itself. */

sdks/python/apache_beam/runners/worker/data_sampler.py

@@ -81,10 +81,10 @@ class ExceptionMetadata:
   # The repr-ified Exception.
   msg: str
 
-  # The transform where the exception occured.
+  # The transform where the exception occurred.
   transform_id: str
 
-  # The instruction when the exception occured.
+  # The instruction when the exception occurred.
   instruction_id: str