bake should not skip compose model normalization

[ndeloof]

closes #906

[crazy-max]

Looks like this test fails: https://github.com/docker/buildx/actions/runs/4989923431/jobs/8934490857?pr=1803#step:4:581

#17 67.71 === CONT  TestReadTargetsWithDotCompose
#17 67.71     bake_test.go:366: 
#17 67.71         	Error Trace:	/src/bake/bake_test.go:366
#17 67.71         	Error:      	Not equal: 
#17 67.71         	            	expected: "Dockerfile.webapp"
#17 67.71         	            	actual  : "Dockerfile"
#17 67.71         	            	
#17 67.71         	            	Diff:
#17 67.71         	            	--- Expected
#17 67.71         	            	+++ Actual
#17 67.71         	            	@@ -1 +1 @@
#17 67.71         	            	-Dockerfile.webapp
#17 67.71         	            	+Dockerfile
#17 67.71         	Test:       	TestReadTargetsWithDotCompose

I recall we needed to skip normalization to be able to merge compose files otherwise normalization overrides some fields.

[ndeloof]

@crazy-max looking at failing test I guess this is an issue we need to fix on Compose as well

[ndeloof]

I'm not sure I understand the fix covered by TestReadTargetsWithDotCompose. sanitizeTargetName to convert web.app with web_app then merge targets with same resulting name, while those were distinct in compose