[FLINK-35281][hotfix][cdc-common] FlinkEnvironmentUtils#addJar add each jar only once

[loserwang1024]

Current org.apache.flink.cdc.composer.flink.FlinkEnvironmentUtils#addJar will be invoked for each source and sink.

public static void addJar(StreamExecutionEnvironment env, URL jarUrl) {
    try {
        Class<StreamExecutionEnvironment> envClass = StreamExecutionEnvironment.class;
        Field field = envClass.getDeclaredField("configuration");
        field.setAccessible(true);
        Configuration configuration = ((Configuration) field.get(env));
        List<String> jars =
                configuration.getOptional(PipelineOptions.JARS).orElse(new ArrayList<>());
        jars.add(jarUrl.toString());
        configuration.set(PipelineOptions.JARS, jars);
    } catch (Exception e) {
        throw new RuntimeException("Failed to add JAR to Flink execution environment", e);
    } 

if multiple source or sink share same jar, the par path will be added repeatly. For example, mysql to mysql later.

[loserwang1024]

@yuxiqian , @PatrickRen , CC

[yuxiqian]

Thanks for @loserwang1024's contribution, I just left some minor comments.