.github: Update all major dependencies (major)

[ata-no-one]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v5 -> v6
docker/build-push-action	action	major	v6 -> v7
docker/login-action	action	major	v3 -> v4
docker/metadata-action	action	major	v5 -> v6
docker/setup-buildx-action	action	major	v3 -> v4

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⚠️ Warning

Some dependencies could not be looked up. Check the warning logs for more information.

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Release Notes

actions/checkout (actions/checkout)

v6

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• Fix tag handling: preserve annotations and explicit fetch-tags by @​ericsciple in https://github.com/actions/checkout/pull/2356

docker/build-push-action (docker/build-push-action)

v7

Compare Source

docker/login-action (docker/login-action)

v4

Compare Source

docker/metadata-action (docker/metadata-action)

v6

Compare Source

docker/setup-buildx-action (docker/setup-buildx-action)

v4

Compare Source

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