bump Zephyr to tip of main

[mniestroj]

Just try out improvements in main and solve issues early before next Zephyr release.

Revert commit e8794bc5af7b ("samples: dfu: override esp_clk_init() with empty definition"), which was a workaround and there is now a proper fix upstream.

Disable IPv6 for coap_utils tests, to solve Kconfig dependencies issue.

There is SNIPPETS feature, which can be really handy for Golioth SDK purposes.

[github-actions[bot]]

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