chore: new silent install_rgbds

.gitlab/common.sh

 install_rgbds() {
     version=${1:-"0.8.0"}
-    curl -L -o rgbds.tar.xz https://github.com/gbdev/rgbds/releases/download/v$version/rgbds-$version-linux-x86_64.tar.xz
+    curl -s -L -o rgbds.tar.xz https://github.com/gbdev/rgbds/releases/download/v$version/rgbds-$version-linux-x86_64.tar.xz
     mkdir -p rgbds
     mv rgbds.tar.xz rgbds/
-    pushd rgbds
+    pushd rgbds > /dev/null
     tar -xf rgbds.tar.xz
-    popd
+    popd > /dev/null
     export PATH="$CI_PROJECT_DIR/rgbds:$PATH"
     rgbasm --version
 }