[ObjC] Breaking Change: Raise the major version for next release.

Raise the major version for the next ObjC release from `main` to
get things ready for landing breaking changes.

PiperOrigin-RevId: 684131809

Protobuf.podspec

@@ -5,7 +5,7 @@
 # dependent projects use the :git notation to refer to the library.
 Pod::Spec.new do |s|
   s.name     = 'Protobuf'
-  s.version  = '3.30.0'
+  s.version  = '4.30.0'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/protocolbuffers/protobuf'
   s.license  = 'BSD-3-Clause'

version.json

@@ -8,7 +8,7 @@
             "csharp": "3.30-dev",
             "java": "4.30-dev",
             "javascript": "3.30-dev",
-            "objectivec": "3.30-dev",
+            "objectivec": "4.30-dev",
             "php": "4.30-dev",
             "python": "5.30-dev",
             "ruby": "4.30-dev"