Docker compose published environment values computed incorrectly

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

The compose publisher doesn't properly handle all types of value providers and always uses the default value for an environment variable if one is provided. This causes it to ignore overrides in ContainerImageReference and always provide `:latest` as the image name for compose services, even if a user provided a custom `.WithDeploymentImageTag()` value. It likely impacts other environment variables as well.

### Expected Behavior

Custom values should apply to environment based configuration for compose publish output.

### Steps To Reproduce

Add a Docker Compose publish environment (`.AddDockerComposeEnvironment("docker-compose")`) and configure a Project resource with a custom deployment image tag (`.WithDeploymentImageTag((_) => "mycustomtag")`). Publish the app host and check to see the image tag used for the resource.

### Exceptions (if any)

_No response_

### .NET Version info

_No response_

### Anything else?

_No response_