Add flags to swiftly

Author: shahmishal

.github/workflows/swift_package_test.yml

@@ -355,7 +355,7 @@ jobs:
         run: |
           curl -O https://download.swift.org/swiftly/darwin/swiftly.pkg
           installer -pkg swiftly.pkg -target CurrentUserHomeDirectory
-          ~/.swiftly/bin/swiftly init --quiet-shell-followup
+          ~/.swiftly/bin/swiftly init --quiet-shell-followup --assume-yes --skip-install
           . "${SWIFTLY_HOME_DIR:-$HOME/.swiftly}/env.sh"
           hash -r
           echo "${SWIFTLY_HOME_DIR:-$HOME/.swiftly}/bin" >> $GITHUB_PATH