ci: fix with apt-get update

.github/workflows/main.yml

@@ -14,6 +14,7 @@ jobs:
           toolchain: stable
           override: true
       - uses: Swatinem/rust-cache@v1
+      - run: sudo apt-get update
       - run: sudo apt install libwebkit2gtk-4.0-dev libappindicator3-dev libgtk-3-dev libappindicator3-dev
       - uses: actions-rs/cargo@v1
         with:
@@ -30,6 +31,7 @@ jobs:
           toolchain: stable
           override: true
       - uses: Swatinem/rust-cache@v1
+      - run: sudo apt-get update
       - run: sudo apt install libwebkit2gtk-4.0-dev libappindicator3-dev libgtk-3-dev libappindicator3-dev
       - uses: actions-rs/cargo@v1
         with: