OpenAPI: Remove diff-compatibility emptySpace hack

[manusa]

Description

The new model generation approach implemented in #6130, added a hack to add an empty space in some parts of the generated code.

The main purpose was to minimize the number of diffs in the generated code with the previous (Go) approach.
This hack is no longer necessary and should be removed.

kubernetes-client/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/model/ModelGenerator.java

Line 103 in ed694c4

ret.put("emptySpace", " "); // TODO: remove after generator migration, current workaround so that models match with jsonschema2pojo

kubernetes-client/kubernetes-model-generator/openapi/maven-plugin/src/main/resources/templates/model_methods.mustache

Lines 37 to 39 in 4944554

	*{{emptySpace}}
	* (Required)
	*{{emptySpace}}

kubernetes-client/kubernetes-model-generator/openapi/maven-plugin/src/main/resources/templates/model_methods.mustache

Lines 19 to 21 in 4944554

	*{{emptySpace}}
	* (Required)
	*{{emptySpace}}

kubernetes-client/kubernetes-model-generator/openapi/maven-plugin/src/main/resources/templates/model_constructors.mustache

Line 18 in d6e4c22

*{{emptySpace}}

kubernetes-client/kubernetes-model-generator/openapi/maven-plugin/src/main/resources/templates/model_fields.mustache

Lines 25 to 27 in 0c1c753

	*{{emptySpace}}
	* (Required)
	*{{emptySpace}}