Implicit parameters should be provided with a using clause warning since Scala 3.7

[xuwei-k]

compile with latest Scala 3.7 NIGHTLY

3.7.0-RC1-bin-20250215-43f8cdb-NIGHTLY

e2e-grpc/target/jvm-3/src_managed/main/com/thesamet/proto/e2e/service/Service1Grpc.scala:271:12 
[warn] 271 |            executionContext)
[warn]     |            ^^^^^^^^^^^^^^^^
[warn]     |Implicit parameters should be provided with a `using` clause.
[warn]     |This code can be rewritten automatically under -rewrite -source 3.7-migration.
[warn]     |To disable the warning, please use the following option: 
[warn]     |  "-Wconf:msg=Implicit parameters should be provided with a `using` clause:s"

• Implicit parameters should warn at call site in >= 3.7 scala/scala3#22441

I think we should add using in GrpcServicePrinter if scala3_sources

               s"""$call((request: ${method.inputType.scalaType}, observer: $streamObserver[${method.outputType.scalaType}]) => {
-                 |  $serviceImpl.${method.name}(request).onComplete(scalapb.grpc.Grpc.completeObserver(observer))(
+                 |  $serviceImpl.${method.name}(request).onComplete(scalapb.grpc.Grpc.completeObserver(observer))(using
                  |    $executionContext)

ScalaPB/compiler-plugin/src/main/scala/scalapb/compiler/GrpcServicePrinter.scala

Lines 247 to 250 in 261376f

	s"""$call((request: ${method.inputType.scalaType}, observer: $streamObserver[${method.outputType.scalaType}]) => {
	| $serviceImpl.${method.name}(request).onComplete(scalapb.grpc.Grpc.completeObserver(observer))(
	| $executionContext)
	|}))""".stripMargin

[ghostdogpr]

Now that Scala 3.7.0 is released, this becomes really needed.

[ghostdogpr]

Opened #1854 for this