Dockerfile: update to Docker Engine v25.0.1

[thaJeztah]

• relates to After Update to Docker 25.0.0 (buildx v0.12.1), host-gateway in build does not work anymore #2201
• relates to fix "host-gateway-ip" label not set for builder workers moby/moby#47187

Update DOCKER_VERSION to the current release, so that tests run against that version.

[thaJeztah]

Nice! It's failing with v25.0.0, that's what I was hoping to see;

=== FAIL: tests TestIntegration/TestDockerHostGateway/worker=docker (2.54s)
    build.go:432: 
        	Error Trace:	/src/tests/build.go:432
        	            				/src/vendor/github.com/moby/buildkit/util/testutil/integration/run.go:91
        	            				/src/vendor/github.com/moby/buildkit/util/testutil/integration/run.go:205
        	Error:      	Received unexpected error:
        	            	exit status 1
        	Test:       	TestIntegration/TestDockerHostGateway/worker=docker
        	Messages:   	ERROR: unable to derive the IP value for host-gateway: failed to parse host-gateway IP: <nil>
    sandbox.go:128: stdout: /usr/bin/dockerd
    sandbox.go:128: stderr: /usr/bin/dockerd

=== FAIL: tests TestIntegration/TestDockerHostGateway/worker=docker+containerd (2.48s)
    build.go:432: 
        	Error Trace:	/src/tests/build.go:432
        	            				/src/vendor/github.com/moby/buildkit/util/testutil/integration/run.go:91
        	            				/src/vendor/github.com/moby/buildkit/util/testutil/integration/run.go:205
        	Error:      	Received unexpected error:
        	            	exit status 1
        	Test:       	TestIntegration/TestDockerHostGateway/worker=docker+containerd
        	Messages:   	ERROR: unable to derive the IP value for host-gateway: failed to parse host-gateway IP: <nil>
    sandbox.go:128: stdout: /usr/bin/dockerd
    sandbox.go:128: stderr: /usr/bin/dockerd

I'll update it to use v25.0.1 now, which should have the fix; moby/moby#47187

[thaJeztah]

Whoop, and green with v25.0.1 👍