tool: force HTTP/1.1 in curl to prevent hang behind load balancer

When running in our github CI environment, curl sometimes hangs while closing
the download from the nodejs.org server and fails with INTERNAL_ERROR. This is
likely caused by CI running behind some kind of load balancer or proxy that
handles HTTP/2 incorrectly in some minor way, so force curl to use HTTP 1.1.

Updates #8988

Signed-off-by: Val <valerie@tailscale.com>
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Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f