Recommend to use the final version of CDN support for the CocoaPods trunk specs repo (#36237)

packages/flutter_tools/templates/cocoapods/Podfile-ios-objc

+# Using a CDN with CocoaPods 1.7.2 or later can save a lot of time on pod installation, but it's experimental rather than the default.
+# source 'https://cdn.cocoapods.org/'
+
 # Uncomment this line to define a global platform for your project
 # platform :ios, '9.0'
 

packages/flutter_tools/templates/cocoapods/Podfile-ios-swift

+# Using a CDN with CocoaPods 1.7.2 or later can save a lot of time on pod installation, but it's experimental rather than the default.
+# source 'https://cdn.cocoapods.org/'
+
 # Uncomment this line to define a global platform for your project
 # platform :ios, '9.0'
 

packages/flutter_tools/templates/cocoapods/Podfile-macos

+# Using a CDN with CocoaPods 1.7.2 or later can save a lot of time on pod installation, but it's experimental rather than the default.
+# source 'https://cdn.cocoapods.org/'
+
 platform :osx, '10.13'
 
 # CocoaPods analytics sends network stats synchronously affecting flutter build latency.