Transaction stuck after first step execution

Hi,

I'm using the transaction API but it seems the transaction always gets stuck after executing the first step.
I'm using EdgeDB 5.6 on EdgeDB Cloud and Java client library version 0.3.0.

Here is a simple example using Kotlin.
```kotlin
package com.test.edgedbclient

import com.edgedb.driver.EdgeDBClient
import com.edgedb.driver.EdgeDBConnection
import kotlinx.coroutines.future.await

suspend fun main() {
val client = EdgeDBClient(EdgeDBConnection.parse(null, null, true))
val output = client.transaction { tx ->
tx.query(String::class.java, "SELECT 'Hello, World 1!'")
.thenCompose {
println("Output0: $it")
tx.query(String::class.java, "SELECT 'Hello, World 2!'")
}
.thenCompose {
println("Output1: $it")
tx.query(String::class.java, "SELECT 'Hello, World 3!'")
}
}.await()

println("--- Completed ---")
println("Final output: $output")
client.close()
}
```

The output is `Output0: [Hello, World 1!]` from the first step and then it's stuck.

I believe this is happening due to the semaphore in `TransactionImpl` being acquired
https://github.com/edgedb/edgedb-java/blob/3ddbee1455ad0216d96346ceb71e34ec158bc88f/src/driver/src/main/java/com/edgedb/driver/internal/TransactionImpl.java#L98-L114
but never being released in the `executeTransactionStep` method after completion of the step.
https://github.com/edgedb/edgedb-java/blob/3ddbee1455ad0216d96346ceb71e34ec158bc88f/src/driver/src/main/java/com/edgedb/driver/internal/TransactionImpl.java#L71-L96

This issue could be the same as https://github.com/edgedb/edgedb-java/issues/21.

Please let me know if any other details are required.

Thanks