Delete variant of rtc::split that copies the output fields

Bug: webrtc:13579
Change-Id: I065a32704d48d5eed21aee0e9757cac9ecf7aa99
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/261951
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Ali Tofigh <alito@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37160}

rtc_base/string_encode.h

@@ -48,10 +48,6 @@ size_t hex_decode_with_delimiter(ArrayView<char> buffer,
 // single, empty, field.
 std::vector<absl::string_view> split(absl::string_view source, char delimiter);
 
-size_t split(absl::string_view source,
-             char delimiter,
-             std::vector<std::string>* fields);
-
 // Splits the source string into multiple fields separated by delimiter,
 // with duplicates of delimiter ignored.  Trailing delimiter ignored.
 size_t tokenize(absl::string_view source,