kotlinx coroutines versions are out of date (in bazel)

[jeffzoch]

IO_GRPC_GRPC_KOTLIN_ARTIFACTS = [
    "com.google.guava:guava:29.0-jre",
    "com.squareup:kotlinpoet:1.5.0",
    "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.5",
    "org.jetbrains.kotlinx:kotlinx-coroutines-debug:1.3.5",
]

has a few pretty old versions with breaking changes occurring in channel apis. I get errors when trying to use 1.4.3 (which itself is out of date with newer versions). org.jetbrains.kotlinx:kotlinx-coroutines-core can probably just be org.jetbrains.kotlinx:kotlinx-coroutines-core-jvm too.

The rules in WORKSPACE are also old but those are easier to opt out of it seems since they are only loaded if they dont exist already

[Kernald]

Compiling gRPC-Kotlin with 1.4.3 was fine for me, as far as I can tell. Migrating to 1.5 will require a tiny bit of work at least:

stub/src/main/java/io/grpc/kotlin/ServerCalls.kt:269:34: warning: 'offer(E): Boolean' is deprecated. Deprecated in the favour of 'trySend' method                               
            if (!requestsChannel.offer(message)) {                                                                                                                                                                   
                                 ^                 

Switching to trySend is quite straightforward (but didn't exist before 1.5.0, so would be a breaking change).

[jamesward]

cc @aragos

[jesseschalken]

I think this was fixed in #327 and #340