CI: fix build on non-x86 Linux platforms

The CI build script is useful to build OBS Studio even outside the CI
environment. However, the current script hard codes adding the 'amd64'
architecture to dpkg, the Debian/Ubuntu package management database.
This breaks the system when run on non-x86 machines. e.g., a
linux-aarch64 VM running on an Apple silicon macbook. Fixing the system
requires telling dpkg to remove 'amd64' again with 'sudo dpkg
--remove-architecture amd64'

As the CI build always runs on an amd64 machine, adding amd64 is not
necessary and can be safely removed.

Signed-off-by: Grant Likely <[email protected]>

CI/linux/01_install_dependencies.sh

@@ -98,7 +98,6 @@ install_dependencies() {
          libpulse-dev libsndio-dev libspeexdsp-dev libudev-dev libv4l-dev libva-dev libvlc-dev libdrm-dev"
     )
 
-    sudo dpkg --add-architecture amd64
     sudo apt-get -qq update
 
     for DEPENDENCY in "${BUILD_DEPS[@]}"; do