Flaky: `TestBakeCallCheckFlag`

[crazy-max]

since #2556

https://github.com/docker/buildx/actions/runs/9781672942/job/27006277267#step:7:422

=== FAIL: tests TestIntegration/TestBakeCallCheckFlag/worker=docker-container (2.04s)
    bake.go:1086: 
        	Error Trace:	/src/tests/bake.go:1086
        	            				/src/vendor/github.com/moby/buildkit/util/testutil/integration/run.go:96
        	            				/src/vendor/github.com/moby/buildkit/util/testutil/integration/run.go:211
        	Error:      	Received unexpected error:
        	            	invalid character '/' after top-level value
        	Test:       	TestIntegration/TestBakeCallCheckFlag/worker=docker-container
    --- FAIL: TestIntegration/TestBakeCallCheckFlag/worker=docker-container (2.04s)