This fixes the cli erroring out if the variable is set to an empty
value.

```
$ export DOCKER_BUILDKIT=
$ docker version
DOCKER_BUILDKIT environment variable expects boolean value: strconv.ParseBool: parsing "": invalid syntax
```

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
(cherry picked from commit ff7f76a)
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

[23.0 backport] Handle empty DOCKER_BUILDKIT like unset

These tests were deliberately producing errors as part of the test, but
printing those errors could be confusing / make it more difficult to find
actual test-failures.

Before this patch:

    === RUN   TestVolumeCreateErrors
    Error: conflicting options: either specify --name or provide positional arg, not both
    Error: "create" requires at most 1 argument.
    See 'create --help'.

    Usage:  create [OPTIONS] [VOLUME] [flags]

    Create a volume
    Error: error creating volume
    --- PASS: TestVolumeCreateErrors (0.00s)
    PASS

With this patch applied:

    === RUN   TestVolumeCreateErrors
    --- PASS: TestVolumeCreateErrors (0.00s)
    PASS

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit db827d5)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 0dec5d2)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 1aaa179)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

The --format=json option was added for all inspect commands, but was not implemented
for "docker info". This patch implements the missing option.

Before this patch:

    docker info --format=json
    json

With this patch applied:

    docker info --format=json
    {"ID":"80c2f18a-2c88-4e4a-ba69-dca0eea59835","Containers":7,"ContainersRunning":"..."}

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 46234b8)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 80640bc)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

The --format=json option was added for all inspect commands, but was not
implemented for "docker version". This patch implements the missing option.

Before this patch:

    docker version --format=json
    json

With this patch:

    docker version --format=json
    {"Client":{"Platform":{"Name":""},"Version":"24.0.0-dev","ApiVersion":"..."}}

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 23bd746)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: David Karlsson <david.karlsson@docker.com>
(cherry picked from commit 25ed784)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: David Karlsson <david.karlsson@docker.com>
(cherry picked from commit 341c843)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Bumps [docker/bake-action](https://github.com/docker/bake-action) from 2 to 3.
- [Release notes](https://github.com/docker/bake-action/releases)
- [Commits](docker/bake-action@v2...v3)

---
updated-dependencies:
- dependency-name: docker/bake-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
(cherry picked from commit 6c4c3c2)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

[23.0 backport] ci: add validation for generated docs, bump docker/bake-action

[23.0 backport] fix docker info, docker version --format=json not outputting json format

[23.0 backport] volumes: prune: add --all / -a option

Signed-off-by: Chris Chinchilla <chris.ward@docker.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit e693e7f)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

no changes in vendored files

full diff: moby/moby@v23.0.3...v23.0.4

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

[23.0 backport] Docs freshness updates

[23.0] vendor: github.com/docker/docker v23.0.4