tools: don’t emit illegal utf-8 from icutrim/iculslocs

- argv[0] was being emitted into a utf-8 stream, but argv[0] may
not be legal utf-8
- fix by not emitting argv[0] (was only for a source comment)
- partially resolves #17077

PR-URL: #19756
Fixes: #17077
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Nikolai Vavilov <vvnicholas@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

tools/icu/iculslocs.cc

@@ -270,9 +270,9 @@ int list(const char* toBundle) {
   if (bf != NULL) {  // NOLINT (readability/null_usage)
     // write the HEADER
     fprintf(bf,
-            "// Warning this file is automatically generated\n"
-            "// Updated by %s based on %s:%s.txt\n",
-            PROG,
+            "// NOTE: This file was generated during the build process.\n"
+            "// Generator: tools/icu/iculslocs.cc\n"
+            "// Input package-tree/item: %s/%s.res\n",
             packageName.data(),
             locale);
     fprintf(bf,