fix: format CI workflow and add pip caching step

Author: winterx64

.github/workflows/ci.yml

@@ -2,7 +2,7 @@ name: CI
 
 on:
   push:
-    branches: [ "master", "main" ]
+    branches: ["master", "main"]
   pull_request:
 
 jobs:
@@ -18,6 +18,15 @@ jobs:
         with:
           python-version: "3.11"
 
+      # 🔹 Cache pip downloads (speed boost)
+      - name: Cache pip
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+
       - name: Install dependencies
         run: |
           pip install -r requirements.txt