PR #2138: Exclude Windows-specific CCTZ source files in podspec

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/2138

## Summary
- This PR excludes Windows-specific CCTZ source files (`absl/time/internal/cctz/src/*_win.cc`) in the generated `abseil.podspec`.

## Description
- The CCTZ time zone library in Abseil contains platform-specific source files like `absl/time/internal/cctz/src/time_zone_name_win.cc` intended only for Windows builds. When consuming Abseil via CocoaPods on Apple platforms (iOS, macOS, tvOS, watchOS, visionOS), these Windows-specific files are unnecessary and cause build errors.

## End-to-End Build Test
- Tested integration with CocoaPods client project (`gRPC Sample` on iOS Simulator `arm64` and `x86_64`).
- `xcodebuild -project Pods.xcodeproj -target abseil` passed with **`** BUILD SUCCEEDED **`**.

Merge 47d77a572d5271747d3b3fecba4786ed1b469520 into b7adf83dccc73cd897fa6938978d96dce63a5d52

Merging this change closes #2138

PiperOrigin-RevId: 974534125
Change-Id: Ief81630244067bb3e385511324b1fffd986adea6

absl/abseil.podspec.gen.py

diff --git a/absl/abseil.podspec.gen.py b/absl/abseil.podspec.gen.py
index e19f951..73eb9de 100755
--- a/absl/abseil.podspec.gen.py
+++ b/absl/abseil.podspec.gen.py
@@ -49,6 +49,7 @@
   s.tvos.deployment_target = '12.0'
   s.watchos.deployment_target = '4.0'
   s.visionos.deployment_target = '1.0'
+  s.exclude_files = [ 'absl/time/internal/cctz/src/*_win.cc' ]
   s.subspec 'xcprivacy' do |ss|
     ss.resource_bundles = {
       ss.module_name => 'PrivacyInfo.xcprivacy',
@@ -189,7 +190,11 @@
   # Since CocoaPods treats header_files a bit differently from bazel,
   # this won't generate a header_files field so that all source_files
   # are considered as header files.
-  srcs = sorted(set(rule.hdrs + rule.textual_hdrs + rule.srcs))
+  srcs = [
+      s
+      for s in sorted(set(rule.hdrs + rule.textual_hdrs + rule.srcs))
+      if not s.endswith("_win.cc")
+  ]
   write_indented_list(
       f, "{indent}{var}.source_files = ".format(indent=indent, var=spec_var),
       srcs)