Delete deprecated FieldTrials::CreateNoGlobal

FieldTrials class always represent non global field trials, thus this
factory name is obsolete.

Bug: webrtc:42220378
Change-Id: I64c64092b205f309741a4b7f4119e311eb2a8015
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/403100
Commit-Queue: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Auto-Submit: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#45277}
diff --git a/api/field_trials.h b/api/field_trials.h
index 09aa1dc..5cb36bf 100644
--- a/api/field_trials.h
+++ b/api/field_trials.h
@@ -70,12 +70,6 @@
   // Setting empty `group` is valid and removes the `trial`.
   void Set(absl::string_view trial, absl::string_view group);
 
-  // TODO: bugs.webrtc.org/42220378 - Delete after August 1, 2025.
-  [[deprecated]]
-  static std::unique_ptr<FieldTrials> CreateNoGlobal(absl::string_view s) {
-    return std::make_unique<FieldTrials>(s);
-  }
-
  private:
   explicit FieldTrials(flat_map<std::string, std::string> key_value_map)
       : key_value_map_(std::move(key_value_map)) {}