Update several test / plugin dependencies in 3.4.x (reactor#2992)

This commit upgrades the following dependencies:
 - plugin download to v5.0.4
 - plugin spotless to v6.4.1
 - jmh to v1.35
 - plugin artifactory to v4.28.1
 - plugin gradle.enterprise to v3.9
 - perf benchmark dependency reactor-extra to v3.4.7

These have been notified by Renovate, but it currently only opens PRs
against the main branch.

Supersedes and closes reactor#2988.
Supersedes and closes reactor#2986.
Supersedes and closes reactor#2985.
Supersedes and closes reactor#2975.
Supersedes and closes reactor#2976.
Supersedes and closes reactor#2966.

gradle/libs.versions.toml

@@ -2,12 +2,12 @@
 # Baselines, should be updated on every release
 baseline-core-api = "3.4.16"
 baselinePerfCore = "3.4.16"
-baselinePerfExtra = "3.4.6"
+baselinePerfExtra = "3.4.7"
 
 # Other shared versions
 asciidoctor = "3.3.2"
 bytebuddy = "1.12.8"
-jmh = "1.34"
+jmh = "1.35"
 junit = "5.8.2"
 kotlin = "1.5.32"
 reactiveStreams = "1.0.3"
@@ -39,15 +39,15 @@ testNg = "org.testng:testng:7.5"
 throwingFunction = "com.pivovarit:throwing-function:1.5.1"
 
 [plugins]
-artifactory = { id = "com.jfrog.artifactory", version = "4.27.1" }
+artifactory = { id = "com.jfrog.artifactory", version = "4.28.1" }
 asciidoctor-convert = { id = "org.asciidoctor.jvm.convert", version.ref = "asciidoctor" }
 asciidoctor-pdf = { id = "org.asciidoctor.jvm.pdf", version.ref = "asciidoctor" }
 bnd = { id = "biz.aQute.bnd.builder", version = "6.2.0" }
-download = { id = "de.undercouch.download", version = "5.0.2" }
+download = { id = "de.undercouch.download", version = "5.0.4" }
 japicmp = { id = "me.champeau.gradle.japicmp", version = "0.4.0" }
 jcstress = { id = "io.github.reyerizo.gradle.jcstress", version = "0.8.13" }
 kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
 nohttp = { id = "io.spring.nohttp", version = "0.0.10" }
 shadow = { id = "com.github.johnrengelman.shadow", version = "7.1.2" }
-spotless = { id = "com.diffplug.spotless", version = "6.3.0" }
+spotless = { id = "com.diffplug.spotless", version = "6.4.1" }
 testsets = { id = "org.unbroken-dome.test-sets", version = "4.0.0" }

settings.gradle

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 plugins {
-	id "com.gradle.enterprise" version "3.8.1"
+	id "com.gradle.enterprise" version "3.9"
 }
 
 rootProject.name = 'reactor'