api/types/container: remove deprecated ExecOptions.Detach

This field was deprecated in 0c182d4d57,
which should be included in a 28.x release, but we don't need to carry
it in the new module.

We should also considering duplicating the `ExecOptions` type as a client
option, and renaming it to `ExecCreateRequest`, so that we can decouple
client options from the shape of the request.

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

api/types/container/exec.go

@@ -22,9 +22,6 @@ type ExecOptions struct {
 	Env          []string // Environment variables
 	WorkingDir   string   // Working directory
 	Cmd          []string // Execution commands and args
-
-	// Deprecated: the Detach field is not used, and will be removed in a future release.
-	Detach bool
 }
 
 // ExecStartOptions is a temp struct used by execStart