Add Kotest assertions core library to nativeTest dependencies

The Kotest assertions core library was added to `libs.versions.toml` and included as a dependency in the `nativeTest` configuration. This prepares the project for more comprehensive and expressive test assertions in native tests. Unused imports in `BitstringTest.kt` were also cleaned up to simplify the code.

Author: sksamuel

kotest-native/build.gradle.kts

@@ -27,6 +27,7 @@ kotlin {
       nativeTest {
          dependencies {
             implementation(libs.kotest.framework.engine)
+            implementation(libs.kotest.assertions.core)
          }
       }
    }

kotest-native/gradle/libs.versions.toml

@@ -4,6 +4,7 @@ kotlin = "2.2.0"
 
 [libraries]
 kotest-framework-engine = { module = "io.kotest:kotest-framework-engine", version.ref = "kotest" }
+kotest-assertions-core = { module = "io.kotest:kotest-assertions-core", version.ref = "kotest" }
 
 [plugins]
 kotlin-multiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }

kotest-native/src/nativeTest/kotlin/io/kotest/examples/native/BitstringTest.kt

@@ -1,9 +1,5 @@
 package io.kotest.examples.native
 
-import io.kotest.assertions.throwables.shouldThrowAny
-import io.kotest.core.spec.style.DescribeSpec
-import io.kotest.matchers.shouldBe
-
 //class BitstringTest : DescribeSpec() {
 //   init {
 //      describe("bit strings") {