wendelin.core: v↑ 2.0.alpha2.post2 -> 2.0.alpha3

New WC2 alpha release provides us with various small fixes:

    wendelin.core@5e5ad598...7ce0978d

It also prepares upgrading SlapOS go default version to v1.18
(WC2 alpha2 doesn't work with go1.18).

Tests passed: https://erp5js.nexedi.net/#/test_result_module/20221221-5FEF9030

/reviewed-on !1309