Update main.yml (#4)

Author: SebastianSpeitel

.github/workflows/main.yml

@@ -16,7 +16,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - uses: actions/cache@v3.0.2
+    - uses: actions/cache@v4
       with:
         path: |
           ~/.cargo/bin/