Remove Cocoapods script and references (grpc#1439)

Motivation:

We no longer support Cocoapods, so we should remove any
references to them from the repo.

Modifications:

- Remove pod related tooling and documentation.

Result:

More accurate documentation. Cleaner repo.

Examples/Google/SpeechToText/README.md

@@ -29,8 +29,6 @@ This project requires a Google Cloud API Key. Please [register](https://cloud.go
 
 ## Helpful Links
 * [Getting Started with Speech APIs](https://cloud.google.com/speech-to-text/docs/quickstart)
-* [CocoaPods](https://cocoapods.org/)
-* [gRPC-Swift CocoaPod](https://cocoapods.org/pods/gRPC-Swift)
 
 NOTE: Implementation of the AudioStreamManager is based off of [Google's Example Audio Streaming](https://github.com/GoogleCloudPlatform/ios-docs-samples/blob/master/speech/Swift/Speech-gRPC-Streaming/Speech/AudioController.swift)
 

README.md

@@ -22,10 +22,10 @@ insecure channels.
 gRPC Swift has recently been rewritten on top of [SwiftNIO][swift-nio] as
 opposed to the core library provided by the [gRPC project][grpc].
 
-Version | Implementation | Branch                 | `protoc` Plugin         | CocoaPod              | Support
---------|----------------|------------------------|-------------------------|-----------------------|-----------------------------------------
-1.x     | SwiftNIO       | [`main`][branch-new]   | `protoc-gen-grpc-swift` | [gRPC-Swift][pod-new] | Actively developed and supported
-0.x     | gRPC C library | [`cgrpc`][branch-old]  | `protoc-gen-swiftgrpc`  | [SwiftGRPC][pod-old]  | No longer developed; security fixes only
+Version | Implementation | Branch                 | `protoc` Plugin         | Support
+--------|----------------|------------------------|-------------------------|-----------------------------------------
+1.x     | SwiftNIO       | [`main`][branch-new]   | `protoc-gen-grpc-swift` | Actively developed and supported
+0.x     | gRPC C library | [`cgrpc`][branch-old]  | `protoc-gen-swiftgrpc`  | No longer developed; security fixes only
 
 The remainder of this README refers to the 1.x version of gRPC Swift.
 
@@ -81,21 +81,6 @@ Alternatively, gRPC Swift can be manually integrated into a project:
 1. Add the generated project to your own project, and
 1. Add a build dependency on `GRPC`.
 
-#### CocoaPods
-
-gRPC Swift is currently available [from CocoaPods][pod-new]. To integrate, add
-the following line to your `Podfile`:
-
-```ruby
-    pod 'gRPC-Swift', '~> 1.0.0'
-```
-
-Then, run `pod install` from command line and use your project's generated
-`.xcworkspace` file. You might also need to add `use_frameworks!` to your `Podfile`.
-
-*⚠️ If you have conficting modules as a result of having a transitive
-dependency on '[gRPC-Core][grpc-core-pod]' see [grpc/grpc-swift#945][grpc-swift-945].*
-
 ### Getting the `protoc` Plugins
 
 Binary releases of `protoc`, the Protocol Buffer Compiler, are available on
@@ -111,14 +96,6 @@ To install these plugins, just copy the two executables (`protoc-gen-swift` and
 that is part of your `PATH` environment variable. Alternatively the full path to
 the plugins can be specified when using `protoc`.
 
-Alternatively, you can get the latest precompiled version of the plugins by adding
-the following line to your `Podfile`:
-
-```ruby
-    pod 'gRPC-Swift-Plugins'
-```
-The plugins are available in the `Pods/gRPC-Swift-Plugins/` folder afterwards.
-
 #### Homebrew
 
 The plugins are available from [homebrew](https://brew.sh) and can be installed with:
@@ -178,15 +155,11 @@ Please get involved! See our [guidelines for contributing](CONTRIBUTING.md).
 [docs-tutorial]: ./docs/basic-tutorial.md
 [docs-interceptors-tutorial]: ./docs/interceptors-tutorial.md
 [grpc]: https://github.com/grpc/grpc
-[grpc-core-pod]: https://cocoapods.org/pods/gRPC-Core
-[grpc-swift-945]: https://github.com/grpc/grpc-swift/pull/945
 [protobuf-releases]: https://github.com/protocolbuffers/protobuf/releases
 [swift-nio-platforms]: https://github.com/apple/swift-nio#supported-platforms
 [swift-nio]: https://github.com/apple/swift-nio
 [swift-protobuf]: https://github.com/apple/swift-protobuf
 [xcode-spm]: https://help.apple.com/xcode/mac/current/#/devb83d64851
-[pod-new]: https://cocoapods.org/pods/gRPC-Swift
-[pod-old]: https://cocoapods.org/pods/SwiftGRPC
 [branch-new]: https://github.com/grpc/grpc-swift/tree/main
 [branch-old]: https://github.com/grpc/grpc-swift/tree/cgrpc
 [examples-out-of-source]: https://github.com/grpc/grpc-swift/tree/main/Examples

docs/plugin.md

@@ -96,9 +96,7 @@ desired, and setting `KeepMethodCasing=true` will yield stubs named `Foo`.
 The **GRPCModuleName** option allows the name of the gRPC Swift runtime module
 to be specified. The value, if not specified, defaults to "GRPC".
 
-*Note: most users will not need to use this option. It is intended as a
-workaround for CocoaPods users who may end up with a transitive dependency on
-the gRPC core C library whose module name is also "GRPC".*
+*Note: most users will not need to use this option.*
 
 ### SwiftProtobufModuleName