fix shellcheck with swiftly

Author: ktoso

docker/install_swiftly.sh

@@ -21,7 +21,8 @@ apt-get install -y curl
 curl -O "https://download.swift.org/swiftly/linux/swiftly-$(uname -m).tar.gz"
 tar zxf "swiftly-$(uname -m).tar.gz"
 ./swiftly init --assume-yes
-. "${SWIFTLY_HOME_DIR:-$HOME/.local/share/swiftly}/env.sh"
+disable=SC1091 # we're ok to not validate the swiftly script
+. "${SWIFTLY_HOME_DIR:-$HOME/.local/share/swiftly}/env.sh" && \
 hash -r
 
 swiftly install 6.1.2 --assume-yes --use