Set apiVersion and languageVersion to 2.0 to ensure backwards compatibility

[hugoncosta]

Address #9032 by setting apiVersion and languageVersion to 2.0. This ensures that the code can be compiled with Kotlin 2.2.0+ but users as low as 1.9.0 are able to run this without being forced to update. For reference, 2.2.0 supports compilation as low as 1.6.0.

Compiled locally, seems to work fine, but my laptop is not setup to compile the Android modules btw

[yschimke]

This is pointless as is, unless you also update okio. OkHttp might be compatible, but it relies on very recent versions of Okio which arent.

Can you start there and we can happily follow their lead. Mostly the same maintainers I know.

https://github.com/square/okio/blob/master/build.gradle.kts

[hugoncosta]

Sorry about that - not really used to these workflows + I don't have an Android SDK on my machine. I think this should be it 🤞

[hugoncosta]

I think I have found an easier path, and especially one that doesn't require us to change much - the source code is already 2.0 compatible, only the tests aren't, and they don't need to be, so why bother? The change is now focusing only on "main" source sets, leaving the tests to use any 2.0+ feature.

[Goooler]

Suggested change

	// Configure all projects' source sets (jvm and kmp)
	plugins.matching { it.javaClass.name.startsWith("org.jetbrains.kotlin") }.configureEach {
	kotlinExtension.sourceSets {
	// Exclude all test source sets (containing Test)
	matching { !it.name.contains("Test", ignoreCase = true) }.all {
	languageSettings {
	apiVersion = "2.0"
	languageVersion = "2.0"
	}
	}
	}
	}
	tasks.withType<KotlinCompile>().configureEach {
	if (name.contains("test")) return@configureEach // Skip test source sets.
	compilerOptions {
	// Pin language level to 2.0 to ensure compatibility with older Gradle versions and other libraries that depend on okhttp.
	// https://docs.gradle.org/current/userguide/compatibility.html#kotlin
	languageVersion = org.jetbrains.kotlin.gradle.dsl.KotlinVersion.KOTLIN_2_0
	apiVersion = org.jetbrains.kotlin.gradle.dsl.KotlinVersion.KOTLIN_2_0
	}
	}

[yschimke]

I'll wait for square/okio#1690 to land before this