Move Jenkins post-build tasks to a post{} block

.ci/Jenkinsfile

@@ -51,7 +51,7 @@ def saveArtifacts() {
 def anySuccess = false
 
 pipeline {
-	agent any
+	agent none
 
 	parameters {
 		string(name: 'BUILD_TYPE',
@@ -94,42 +94,37 @@ pipeline {
 				}
 			}
 		}
+	}
 
-		/* This stage has two tasks:
-		   - Trigger downstream jobs if we're on the main job
-		   - Fail this build if all build stages failed
-		   This could be done with two stages and when{} blocks, but then they
-		   would show up separately in the UI (unless JENKINS-44094 happens). */
-		stage('Finish build') {
-			steps {
-				script {
-					if (env.JOB_BASE_NAME == '86Box-TestBuildPleaseIgnore') {
-						["${env.JOB_BASE_NAME}2"].each {
-							try {
-								/* Set next build number for this job. */
-								def job = Jenkins.instance.getItem(it)
-								job.nextBuildNumber = env.BUILD_NUMBER as Integer
-								job.saveNextBuildNumber()
-							} catch (Exception e) {
-								println "[!] Could not set next build number for [$it], make sure all the script approvals are in place"
-							}
-
-							/* Trigger this job. */
-							build propagate: false,
-							      wait: false,
-							      job: it,
-							      parameters: [
-								string(name: 'BUILD_TYPE', value: BUILD_TYPE),
-								string(name: 'BRANCH', value: env.GIT_COMMIT)
-							      ]
+	post {
+		always {
+			script {
+				if (env.JOB_BASE_NAME == '86Box-TestBuildPleaseIgnore') {
+					["${env.JOB_BASE_NAME}2"].each {
+						try {
+							/* Set next build number for this job. */
+							def job = Jenkins.instance.getItem(it)
+							job.nextBuildNumber = env.BUILD_NUMBER as Integer
+							job.saveNextBuildNumber()
+						} catch (Exception e) {
+							println "[!] Could not set next build number for [$it], make sure all the script approvals are in place"
 						}
-					}
 
-					if (!anySuccess) {
-						println "[!] Failing build because all build stages failed"
-						currentBuild.result = 'FAILURE'
+						/* Trigger this job. */
+						build propagate: false,
+						      wait: false,
+						      job: it,
+						      parameters: [
+							string(name: 'BUILD_TYPE', value: BUILD_TYPE),
+							string(name: 'BRANCH', value: env.GIT_COMMIT)
+						      ]
 					}
 				}
+
+				if (!anySuccess) {
+					println "[!] Failing build because all build stages failed"
+					currentBuild.result = 'FAILURE'
+				}
 			}
 		}
 	}