fix: Ensure $(go env GOPATH)/bin exists (#6314)

Author: honnix

boilerplate/flyte/golang_test_targets/download_tooling.sh

@@ -24,17 +24,19 @@ tools=(
 )
 
 # This ensures pflags are up to date.
-make -C $REPO_ROOT/flytestdlib compile
-cp $REPO_ROOT/flytestdlib/bin/pflags $(go env GOPATH)/bin
+make -C "${REPO_ROOT}/flytestdlib" compile
+GO_BIN="$(go env GOPATH)/bin"
+mkdir -p "${GO_BIN}"
+cp "${REPO_ROOT}/flytestdlib/bin/pflags" "${GO_BIN}"
 
-tmp_dir=$(mktemp -d -t gotooling-XXX)
+tmp_dir="$(mktemp -d -t gotooling-XXX)"
 echo "Using temp directory ${tmp_dir}"
-cp -R ../boilerplate/flyte/golang_support_tools/* $tmp_dir
-pushd "$tmp_dir"
+cp -R ../boilerplate/flyte/golang_support_tools/* "${tmp_dir}"
+pushd "${tmp_dir}"
 
 for tool in "${tools[@]}"; do
 	echo "Installing ${tool}"
-	GO111MODULE=on go install $tool
+	GO111MODULE=on go install "${tool}"
 done
 
 popd