docs: Update tutorials to not use bin/post-index-task

[avaamsel]

Updated tutorials to no longer user bin/post-index-task and instead use cURL so users can directly call the Overlord API themselves.

Edited:

• docs/ingestion/native-batch.md
• docs/tutorials/tutorial-batch.md
• docs/tutorials/tutorial-compaction.md
• docs/tutorials/tutorial-delete-data.md
• docs/tutorials/tutorial-ingestion-spec.md
• docs/tutorials/tutorial-retention.md

This PR has:

• been self-reviewed.
• been tested in a test Druid cluster.

[avaamsel]

We confirmed that in the file in tutorial-ingestion-spec was created earlier on in the tutorial and removed the duplicated content in tutorial-batch with the removal of the script from the file.

[317brian]

Thanks for making these changes!

[FrankChen021]

Severity	Findings
P0	0
P1	0
P2	2
P3	0
Total	2

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This is an automated review by Codex GPT-5.5

[FrankChen021]

Severity	Findings
P0	0
P1	0
P2	2
P3	0
Total	2

Severity	Findings
P0	0
P1	0
P2	2
P3	0
Total	2

Reviewed 6 of 6 changed files.

Found 2 tutorial correctness issues after replacing bin/post-index-task with raw curl.

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This is an automated review by Codex GPT-5.5

[FrankChen021]

The latest update fixes the prior tutorial command/path issues, and I found no new high-confidence PR-caused issues.

Reviewed 6 of 6 changed files.

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This is an automated review by Codex GPT-5.5