chore: update to use `gun` 2.1.0 + Erlang/OTP 27 readiness #224

Job	Run time
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, ubuntu24.04)	2m 17s
windows	3m 33s
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, ubuntu22.04)	2m 21s
docker (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1)	2m 15s
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, ubuntu20.04)	2m 30s
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, debian12)	2m 22s
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, debian11)	2m 26s
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, debian10)	2m 28s
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, amzn2023)	2m 25s
linux (ghcr.io/emqx/emqx-builder/5.4-3:1.17.3-27.2-1, el9)	2m 39s
	25m 16s

Provide feedback