Update upstream grpc-swift to v1.6.0

Author: vyshane

Package.resolved

@@ -16,7 +16,7 @@ let package = Package(
             targets: ["CombineGRPC"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/grpc/grpc-swift.git", .exact("1.5.0")),
+        .package(url: "https://github.com/grpc/grpc-swift.git", .exact("1.6.0")),
         .package(url: "https://github.com/CombineCommunity/CombineExt.git", from: "1.5.1"),
     ],
     targets: [

Package.swift

@@ -174,7 +174,7 @@ To generate Swift code from your .proto files, you'll need to first install the
 brew install protobuf
 ```
 
-Next, download the [swift and grpc-swift protoc plugins](https://github.com/grpc/grpc-swift/releases/download/1.5.0/protoc-grpc-swift-plugins-1.5.0.zip). Unarchive the downloaded file and move the binaries from the `bin/` directory to somewhere in your `$PATH`.
+Next, download the [swift and grpc-swift protoc plugins](https://github.com/grpc/grpc-swift/releases/download/1.6.0/protoc-grpc-swift-plugins-1.6.0.zip). Unarchive the downloaded file and move the binaries from the `bin/` directory to somewhere in your `$PATH`.
 
 Now you are ready to generate Swift code from protobuf interface definition files.
 
@@ -203,7 +203,7 @@ Add the package dependency to your `Package.swift`:
 
 ```swift
 dependencies: [
-  .package(url: "https://github.com/vyshane/grpc-swift-combine.git", from: "1.0.7"),
+  .package(url: "https://github.com/vyshane/grpc-swift-combine.git", from: "1.0.8"),
 ],
 ```
 
@@ -212,7 +212,7 @@ dependencies: [
 Add the following line to your `Podfile`:
 
 ```text
-pod 'CombineGRPC', '~> 1.0.7'
+pod 'CombineGRPC', '~> 1.0.6'
 ```
 
 ## Compatibility