refactor(docker): use schema validated getJson

[secustor]

Changes

Use getJson instead of getJsonUnchecked for the docker datasource.

08/13

Ignored following occurrence as we are not using the content at all

renovate/lib/modules/datasource/docker/common.ts

Line 68 in c908d07

await http.getJsonUnchecked(apiCheckUrl, options);

Context

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