fix(exceptions): fix pipeline template exception (spinnaker#3839)

I made changes in my previous PR (spinnaker#3835) to throw a new exception, but didn't update the catch so this is not again generating noise

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

orca-front50/src/main/groovy/com/netflix/spinnaker/orca/front50/spring/DependentPipelineExecutionListener.groovy

@@ -17,9 +17,9 @@
 package com.netflix.spinnaker.orca.front50.spring
 
 import com.netflix.spinnaker.fiat.shared.FiatStatus
-import com.netflix.spinnaker.kork.web.exceptions.ValidationException
 import com.netflix.spinnaker.orca.api.pipeline.models.ExecutionStatus
 import com.netflix.spinnaker.orca.api.pipeline.models.PipelineExecution
+import com.netflix.spinnaker.orca.exceptions.PipelineTemplateValidationException
 import com.netflix.spinnaker.orca.extensionpoint.pipeline.ExecutionPreprocessor
 import com.netflix.spinnaker.orca.front50.DependentPipelineStarter
 import com.netflix.spinnaker.orca.front50.Front50Service
@@ -77,7 +77,7 @@ class DependentPipelineExecutionListener implements ExecutionListener {
        if (V2Util.isV2Pipeline(pipeline)) {
          try {
            return V2Util.planPipeline(contextParameterProcessor, executionPreprocessors, pipeline)
-         } catch (ValidationException ignored) {
+         } catch (PipelineTemplateValidationException ignored) {
            // Really no point in logging this error out here - the user created a bad template, which has no relation
            // to the currently executing pipeline
            return null