git: ignore builtins test output

Drew O'Meara · sbinet · commit 5bf4e3a79611 · 2022-01-31T08:27:14.000+01:00
diff --git a/.gitignore b/.gitignore
@@ -8,3 +8,6 @@ __pycache__
 cover.out
 /junk
 /dist
+
+# tests
+builtin/testfile
