CI: run apt-get update before apt-get install

Make sure our packageset is up-to-date

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

.github/workflows/main.yml

@@ -9,7 +9,9 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Install dependencies
-        run: sudo apt-get install -yq --no-install-suggests --no-install-recommends $UBUNTU_PACKAGES
+        run: |
+          sudo apt-get update -yq
+          sudo apt-get install -yq --no-install-suggests --no-install-recommends $UBUNTU_PACKAGES
       - uses: actions/checkout@v2
       - name: meson
         run: meson builddir