Silence Allstar warnings about Binary Artifacts

Allstar (https://github.com/ossf/allstar/) has been flagging checked-in
binary artifacts in the Pigweed repo on GitHub
(https://github.com/google/pigweed/issues/5). The artifacts in question
are empty ELF files used to test ELF parsing code. Add these files to an
allowlist to silence the warnings.

Change-Id: I14ea5b5617f86b5bd3f390b03612a5a99f6531d2
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/109231
Pigweed-Auto-Submit: Wyatt Hepler <hepler@google.com>
Reviewed-by: Rob Mohr <mohrr@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Ted Pudlik <tpudlik@google.com>
diff --git a/.allstar/binary_artifacts.yaml b/.allstar/binary_artifacts.yaml
new file mode 100644
index 0000000..676e750
--- /dev/null
+++ b/.allstar/binary_artifacts.yaml
@@ -0,0 +1,4 @@
+# Ignore reason: Empty binaries used to test ELF parsing
+ignorePaths:
+- pw_tokenizer/py/elf_reader_test_binary.elf
+- pw_tokenizer/py/example_binary_with_tokenized_strings.elf