Fix Mac CI and schedule a workflow run weekly (#428)

* weekly runs

* Use runner provided python on mac

Author: sagudev

.github/workflows/rust.yml

@@ -7,6 +7,9 @@ on:
   workflow_dispatch:
   merge_group:
     types: [checks_requested]
+  schedule:
+    # Runs at 03:30, every Saturday
+    - cron: "30 3 * * 6"
 
 env:
   RUST_BACKTRACE: 1
@@ -27,7 +30,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install deps
-        run: brew install python llvm yasm
+        run: brew install llvm yasm
       - name: Run sccache-cache
         uses: mozilla-actions/sccache-action@v0.0.3
       - name: Build