pw_build/cmake: Remove deprecated function

Now that _pw_parse_argv_strict is no longer used downstream, remove
it.

Change-Id: I34e8b75594bf42259affbb36832770c1317b9d3e
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/94166
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Ewout van Bekkum <ewout@google.com>
Reviewed-by: Keir Mierle <keir@google.com>
diff --git a/pw_build/pigweed.cmake b/pw_build/pigweed.cmake
index a5916c8..cb5a193 100644
--- a/pw_build/pigweed.cmake
+++ b/pw_build/pigweed.cmake
@@ -37,12 +37,6 @@
   endif()
 endmacro()
 
-# TODO(ewout): Deprecate this once it's no longer in use.
-macro(_pw_parse_argv_strict function start_arg options one multi)
-  pw_parse_arguments_strict(
-      "${function}" "${start_arg}" "${options}" "${one}" "${multi}")
-endmacro()
-
 # Automatically creates a library and test targets for the files in a module.
 # This function is only suitable for simple modules that meet the following
 # requirements: