[Build] Remove jobs to clean-up build maschines

All jobs that use dedicated build agents are now configured to always
clean-up after their execution (regardless of if successful or not).
Therefore special jobs to clean them up are not necessary anymore and
just clutter the Jenkins instance and occupy precious resources.

Author: HannesWell

JenkinsJobs/AutomatedTests/I_unit_tests.groovy

@@ -117,6 +117,11 @@ pipeline {
       }
     }
   }
+  post {
+    always {
+      cleanWs()
+    }
+  }
 }
 
 def pathOf(String path){

JenkinsJobs/Cleanup/Clean_ppcle_buildTest.groovy

@@ -124,6 +124,7 @@ def runSmokeTest(Closure executorAgent, String agentId, String os, String arch,
 		junit keepLongStdio: true, testResults: '**/eclipse-testing/results/xml/*.xml'
 		} finally {
 			archiveArtifacts allowEmptyArchive: true, artifacts: '**/eclipse-testing/results/**, **/eclipse-testing/directorLogs/**, */*.properties, */*.txt'
+			cleanWs()
 		}
 	})
 }