[FLINK-38966][build] Update rsync for GHA to latest v8.0.2 (LTS) for main docs

[MartijnVisser]

What is the purpose of the change

• Update rsync GHA from non-supported version to latest LTS

Brief change log

• Updated rsync GHA to v8.0.2, which is pinned at Burnett01/rsync-deployments@53581df

Verifying this change

Already verified this for legacy docs via #27465

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

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• 9893854 Azure: SUCCESS

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