[JAVA] yaml api java code generation fails

Description

When trying to generate classes/compile OpenApi spec file with version 5.x (tested 5.0.0, 5.1.1) i got error, however with version
4.3.1 compillation runs fine.

[ERROR] failed to read resource listing
com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'openapi': was expecting (JSON String, Number, Array, Object or token 'null', 'true' or 'false')
at [Source: (StringReader); line: 1, column: 8]
at com.fasterxml.jackson.core.JsonParser._constructError (JsonParser.java:1840)

openapi-generator version

5.1.1

OpenAPI declaration file content or url

Command line used for generation

it was generated using maven plugin not using cli

        <plugin>
            <groupId>org.openapitools</groupId>
            <artifactId>openapi-generator-maven-plugin</artifactId>
            <version>5.1.1</version>
            <executions>
                <execution>
                    <goals>
                        <goal>generate</goal>
                    </goals>
                    <configuration>
                        <inputSpec>${project.basedir}/src/main/resources/openapi.yaml</inputSpec>
                        <generatorName>java</generatorName>
                        <generateApis>false</generateApis>
                        <generateSupportingFiles>false</generateSupportingFiles>
                        <generateModelTests>false</generateModelTests>
                        <output>${project.build.directory}/generated-sources</output>
                        <modelPackage>${project.groupId}.arrangement.v2</modelPackage>
                        <configOptions>
                            <additionalModelTypeAnnotations>
                                @lombok.Builder
                                @com.fasterxml.jackson.annotation.JsonInclude(com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL)
                            </additionalModelTypeAnnotations>
                            <dateLibrary>java8</dateLibrary>
                            <library>native</library>
                            <serializationLibrary>jackson</serializationLibrary>
                            <useBeanValidation>false</useBeanValidation>
                        </configOptions>
                    </configuration>
                </execution>
            </executions>
        </plugin>

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

Start by reproducing the Maven plugin configuration against src/main/resources/openapi.yaml with versions 5.1.1 and 4.3.1, using the Java generator settings shown in the issue. Trace the reported resource-listing parse failure and identify a focused regression test or reproduction; done means the YAML specification generates successfully with the affected 5.x version.