Ignore macOS-specific file from git

.gitignore

diff --git a/.gitignore b/.gitignore
index c7cd6d6..9777828 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,6 @@
 /bazel-gitiles
 /bazel-out
 /bazel-testlogs
+
+# macOS-specific file
+.DS_Store