Upgrade to Slither 0.9.6 / Python 3.11

Author: mhluongo

.github/workflows/contracts.yml

@@ -53,9 +53,10 @@ jobs:
           node-version: "14"
           cache: "yarn"
 
-      - uses: actions/setup-python@v4
+      - name: Setup Python
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.8.5
+          python-version: 3.11
 
       - name: Install Solidity
         env:
@@ -66,7 +67,7 @@ jobs:
           solc-select use $SOLC_VERSION
       - name: Install Slither
         env:
-          SLITHER_VERSION: 0.8.0
+          SLITHER_VERSION: 0.9.6
         run: pip3 install slither-analyzer==$SLITHER_VERSION
 
       - name: Install dependencies