remove rvm/GHA code

macos/runtime_setup_stages/install_gems.sh

@@ -11,10 +11,6 @@ if [[ -e /usr/local/rvm/bin/rvm-exec ]]; then
 	RVM_EXEC=/usr/local/rvm/bin/rvm-exec
 elif [[ -e $HOME/.rvm/bin/rvm-exec ]]; then
 	RVM_EXEC=$HOME/.rvm/bin/rvm-exec
-elif [ "${GITHUB_ACTIONS:-false}" = 'true' ]; then
-	\curl -sSL https://get.rvm.io | bash
-	source "$HOME/.rvm/scripts/rvm"
-	RVM_EXEC=$HOME/.rvm/bin/rvm-exec
 else
 	echo "*** ERROR: you must have RVM installed"
 	exit 1
@@ -31,8 +27,6 @@ ALL_RUBIES_OK=true
 for RUBY_VERSION in "${RUBY_VERSIONS[@]}"; do
 	if run_ruby "$RUBY_VERSION" ruby -v &>/dev/null; then
 		echo "Ruby $RUBY_VERSION: ok"
-	elif [ "${GITHUB_ACTIONS:-false}" = 'true' ]; then
-		rvm install "ruby-$RUBY_VERSION" || ( cat "$HOME/.rvm/log/"*_"ruby-$RUBY_VERSION/configure.log" && false )
 	else
 		echo "Ruby $RUBY_VERSION: NOT INSTALLED! Please install it!"
 		ALL_RUBIES_OK=false