Attempt to quell Ubuntu CI error

Ubuntu CI is generating the following error:

E: Failed to fetch https://security.ubuntu.com/ubuntu/pool/main/u/util-linux/uuid-dev_2.39.3-9ubuntu6.2_amd64.deb  404  Not Found [IP: 52.252.163.49 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
Error: Process completed with exit code 100.

This patch updates the repository cache.

.github/workflows/c-cpp.yml

@@ -53,6 +53,7 @@ jobs:
     - name: Install dependencies on Linux
       if: runner.os == 'Linux'
       run: |
+        sudo apt update
         sudo apt install libusb-1.0-0-dev
         sudo apt install libgd-dev
         sudo apt install libgpiod-dev