Remove the interop tests (#261)

They weren't running in CI and haven't been maintained so the other language client no longer even compile cleanly. Given we're not running these tests and they were only basic ping, they aren't providing enough value to justify fixing and maintaining them.

build.gradle.kts

@@ -129,75 +129,6 @@ tasks.test {
 //    Runtime.getRuntime().availableProcessors().div(2))
 }
 
-// Interop Tests
-fun findOnPath(executable: String): Boolean {
-    return System.getenv("PATH").split(File.pathSeparator)
-        .map { Paths.get(it) }
-        .any { Files.exists(it.resolve(executable)) }
-}
-val goOnPath = findOnPath("go")
-val nodeOnPath = findOnPath("node")
-val rustOnPath = findOnPath("cargo")
-
-val externalsDir = File(sourceSets.test.get().resources.sourceDirectories.singleFile, "../external")
-val goPingServer = File(externalsDir, "go/ping-server")
-val goPingClient = File(externalsDir, "go/ping-client")
-val jsPinger = File(externalsDir, "js/pinger")
-val rustPingServer = File(externalsDir, "rust/ping-server")
-val rustPingClient = File(externalsDir, "rust/ping-client")
-
-val goTargets = listOf(goPingServer, goPingClient).map { target ->
-    val name = "go-build-${target.name}"
-    task(name, Exec::class) {
-        workingDir = target
-        commandLine = "go build".split(" ")
-    }
-    name
-}
-
-val rustTargets = listOf(rustPingServer, rustPingClient).map { target ->
-    val name = "rust-build-${target.name}"
-    task(name, Exec::class) {
-        workingDir = target
-        commandLine = "cargo build".split(" ")
-    }
-    name
-}
-
-task("npm-install-pinger", Exec::class) {
-    workingDir = jsPinger
-    commandLine = "npm install".split(" ")
-}
-
-task("interopTest", Test::class) {
-    group = "Verification"
-    description = "Runs the interoperation tests."
-
-    val dependencies = ArrayList<String>()
-    if (goOnPath) dependencies.addAll(goTargets)
-    if (nodeOnPath) dependencies.add("npm-install-pinger")
-    if (rustOnPath) dependencies.addAll(rustTargets)
-    dependsOn(dependencies)
-
-    useJUnitPlatform {
-        includeTags("interop")
-    }
-
-    testLogging {
-        events("PASSED", "FAILED", "SKIPPED")
-    }
-
-    environment("ENABLE_JS_INTEROP", nodeOnPath)
-    environment("JS_PINGER", jsPinger.toString())
-    environment("ENABLE_GO_INTEROP", goOnPath)
-    environment("GO_PING_SERVER", goPingServer.toString())
-    environment("GO_PING_CLIENT", goPingClient.toString())
-    environment("ENABLE_RUST_INTEROP", rustOnPath)
-    environment("RUST_PING_SERVER", rustPingServer.toString())
-    environment("RUST_PING_CLIENT", rustPingClient.toString())
-}
-// End Interop Tests
-
 kotlinter {
     disabledRules = arrayOf("no-wildcard-imports")
 }