remove Jenkins caching (#3594)

Jenkinsfile

@@ -20,19 +20,15 @@ def runStages(nodeDir) {
 				sh "git submodule update --init --recursive"
 			}
 
-			cache(maxCacheSize: 250, caches: [
-				[$class: "ArbitraryFileCache", excludes: "", includes: "**/*", path: "${WORKSPACE}/${nodeDir}/jsonTestsCache"]
-			]) {
-				stage("Preparations") {
-					sh """#!/bin/bash
-					set -e
-					# macOS shows scary warnings if there are old libraries and object files laying around
-					make clean
-					# to allow the following parallel stages
-					make -j${env.NPROC} QUICK_AND_DIRTY_COMPILER=1 update
-					./scripts/setup_scenarios.sh jsonTestsCache
-					"""
-				}
+			stage("Preparations") {
+				sh """#!/bin/bash
+				set -e
+				# macOS shows scary warnings if there are old libraries and object files laying around
+				make clean
+				# to allow the following parallel stages
+				make -j${env.NPROC} QUICK_AND_DIRTY_COMPILER=1 update
+				./scripts/setup_scenarios.sh
+				"""
 			}
 
 			stage("Tools") {