Change/move some gradle modules to be better separated. Let core module be a kotlin lib.

libraries/coroutines/.gitignore

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+/build

libraries/coroutines/build.gradle.kts

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+// TODO: Remove once https://youtrack.jetbrains.com/issue/KTIJ-19369 is fixed
+@Suppress("DSL_SCOPE_VIOLATION")
+plugins {
+    id("java-library")
+    alias(libs.plugins.kotlin.jvm)
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
+dependencies {
+    implementation(libs.coroutines.core)
+}