Use JetBrains runtime for run tasks

allows for better runtime class redefinition

closes #10459

patches/server/0001-Setup-Gradle-project.patch

@@ -28,10 +28,10 @@ index 37dab9e868dbfb019c271a547d975a48ad1cb571..3811c0d849a3eb028ed1a6b7a2d4747f
 +/.factorypath
 diff --git a/build.gradle.kts b/build.gradle.kts
 new file mode 100644
-index 0000000000000000000000000000000000000000..0aa34e8bb81700a3660ba89b3e2a8f53f10ca34c
+index 0000000000000000000000000000000000000000..a457cf30d37037ce09fbe5d26e051b9555ce9982
 --- /dev/null
 +++ b/build.gradle.kts
-@@ -0,0 +1,122 @@
+@@ -0,0 +1,126 @@
 +import io.papermc.paperweight.util.*
 +
 +plugins {
@@ -107,7 +107,11 @@ index 0000000000000000000000000000000000000000..0aa34e8bb81700a3660ba89b3e2a8f53
 +    workingDir = rootProject.layout.projectDirectory
 +        .dir(providers.gradleProperty("paper.runWorkDir").getOrElse("run"))
 +        .asFile
-+    javaLauncher.set(project.javaToolchains.launcherFor(project.java.toolchain))
++    javaLauncher.set(project.javaToolchains.launcherFor {
++        languageVersion.set(JavaLanguageVersion.of(21))
++        vendor.set(JvmVendorSpec.JETBRAINS)
++    })
++    jvmArgs("-XX:+AllowEnhancedClassRedefinition", "-XX:+AllowRedefinitionToAddDeleteMethods")
 +
 +    if (rootProject.childProjects["test-plugin"] != null) {
 +        val testPluginJar = rootProject.project(":test-plugin").tasks.jar.flatMap { it.archiveFile }