fix cache actions version

Author: xoviat

.github/workflows/rust.yml

@@ -17,7 +17,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: ⚡ Cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: |
           ~/.cargo/registry