[FLINK-38727][tests] Remove checkpointing test startup delay

[Shekharrajak]

What is the purpose of the change

restoring fast test startup while retaining the existing standalone-cluster startup grace period.

Brief change log

Verifying this change

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (yes / no)
• The serializers: (yes / no / don't know)
• The runtime per-record code paths (performance sensitive): (yes / no / don't know)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (yes / no / don't know)
• The S3 file system connector: (yes / no / don't know)

Documentation

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CI report:

• 78caa6c Azure: SUCCESS

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