.gitignore: Ignore bazel-deps's target/ folder

Change-Id: I861b19820b462a72903396a1e80849ed18dc7d5d
diff --git a/.gitignore b/.gitignore
index b3b6b38..99a16b9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /bazel-*
 /base/*.tar
 /jenkins/*.tar
+/target/