Reduce YJIT runs on macOS [ci skip]

MacOs concurrency on GitHub Actions is limited, and the
performance is relatively poor.

.github/workflows/yjit-macos.yml

@@ -9,8 +9,8 @@ jobs:
         yjit_opts: [
           "--yjit",
           "--yjit --yjit-call-threshold=1 --yjit-max-versions=1",
-          "--yjit --yjit-call-threshold=1",
-          "--yjit --yjit-call-threshold=2"
+          # "--yjit --yjit-call-threshold=1",
+          # "--yjit --yjit-call-threshold=2"
         ]
       fail-fast: false
     env: